Matemáticas de 3.º de Primaria

In Year 3, children learn to recall and use division facts for the 3, 4 and 8 multiplication tables, solving calculations within 100. They calculate mathematical statements using the division (÷) and equals (=) signs, connecting division directly to multiplication by understanding both sharing amounts into equal parts and grouping items into equal sets.

A common mistake occurs when children fail to connect division to their known multiplication facts. When faced with a missing number in a problem such as 24 ÷ ? = 3, children often guess or try to subtract instead of asking themselves what number multiplies by 3 to make 24. Children also frequently confuse the number of groups with the size of each group when sharing items out.

Practice tasks range from contextual word problems to missing-number tables. Children work with templates such as:

• How many packs will there be and How many in one row to apply division to real-world groupings;
• What was it divided by (division table) and Division within the table (to 100) to build calculation fluency;
• Check the division and find the mistake and Which sharing gives more per person to compare results and spot errors.

In Year 3, children move beyond handling pounds and pence separately. They combine both symbols (£ and p) to add up the cost of several items and subtract amounts to work out change from given notes or coins.

A common mistake occurs when crossing the boundary between pounds and pence. Children often treat amounts like ordinary numbers and forget that 100 pence make one pound, leading to errors such as subtracting 40p from £1 and incorrectly writing 40p or 50p instead of 60p, or simply subtracting the smaller digit from the larger regardless of place value.

Typical practice tasks use everyday shopping scenarios. Children might solve problems such as:

• How much do several items cost: adding multiple prices together to find a total.
• Is there enough money: comparing a set of coins or notes against a target price.
• Shopping and change: calculating how much change is returned after a purchase, or spotting errors in tasks like Change: fix the mistake.

In Year 3, children build on everyday date vocabulary by knowing the exact number of days in each month, a regular year (365), and a leap year (366). They use this knowledge alongside the 7-day cycle of the week to calculate forward and backward, working out what day of the week it will be in a set number of days or finding how much time passes between two calendar dates.

A common mistake occurs when children count days inclusively, counting both the starting date and the ending date instead of measuring the days that actually pass between them. Children also easily miscalculate when time crosses into a new month if they forget which months have 30 or 31 days, or overlook the extra day in February during a leap year.

Typical practice tasks include finding how many days between marked dates on a calendar, deciding if a statement about days passing is true or false, or spotting and fixing an error in someone else's day count. Children also solve problems such as determining which day of the week will it be or working out what day was it some days ago.

In Year 3, children build on knowing that there are 60 minutes in an hour and 24 hours in a day to calculate how much time has passed. They work out durations between given times, calculate start times, and compare events to decide which was quicker, slower, earlier, or later. They also convert simple whole hours into minutes and sequence events throughout a daily schedule.

A frequent stumbling block is treating time like standard decimal numbers. Because an hour has 60 minutes rather than 100, children often mistakenly calculate differences by subtracting as if using base ten—for example, thinking the interval between 2:45 and 3:15 is 70 minutes instead of 30. They can also confuse start and end points when working backwards to find when an activity began.

Worksheet tasks bring this into practical, everyday contexts using templates such as:

• Time duration (how long?) and How many minutes have passed? to find elapsed time.
• What time did it start? to work backwards from a finish time.
• Hours to minutes: choose the correct answer and Convert hours into minutes to practise basic unit conversion.
• The day plan: put the times in order and How much longer one lasted than the other to sequence events and compare their lengths.

In Year 3, children solve missing number problems where an empty box represents an unknown value. Working with numbers up to 1000, they apply their addition and subtraction facts alongside inverse relationships to deduce what belongs in the box. Instead of simply calculating left-to-right, they learn that the equals sign means both sides of the equation must have the exact same total.

A common mistake is treating the equals sign as an instruction to perform the visible operation on the two given numbers. For example, in an equation such as □ – 30 = 50 or 45 + □ = 100, a child might subtract to get 20 or add to get 145. Children also struggle with subtraction when the box is at the beginning, finding it harder to recognise that they must add the remaining parts to find the original whole.

Practice tasks reinforce this balance visually and numerically. Typical activities include:

• Finding the weight of a hidden block on a balanced scale.
• Finding a missing addend within a sum of two or three numbers.
• Working out what starting number an amount was taken from in subtraction.
• Working out how many more are needed to make both sides of an equation equal.

In Year 3, children build on their knowledge of the 2, 5, and 10 times tables to recall and use facts for the 3, 4, and 8 multiplication tables. They connect visual models to written equations, learning to calculate products up to 100 and understand the relationship between factors.

A common difficulty occurs when children rely on counting up in steps rather than recalling known facts, which frequently leads to off-by-one errors. Children also easily confuse facts between the 4 and 8 times tables if they do not yet recognise that multiplying by 8 is simply doubling the product of 4.

Worksheet tasks reinforce these facts through both visual and numerical formats. Children may determine totals using how many dots in the array and equal groups altogether, identify errors in check the multiplication and find the mistake, solve for an unknown value in missing factor grids, or compare calculations in which product is larger and by how much.

Children learn to recognize that addition can be done in any order without changing the total. Building on adding three one-digit numbers, they look at additions with three or four terms and reorder them to calculate efficiently, spotting pairs that are easy to add together mentally.

A typical error occurs when children overgeneralize this rule to subtraction, wrongly assuming that numbers can be swapped in any calculation. When adding, children also frequently stick to calculating strictly from left to right out of habit, overlooking convenient combinations and increasing arithmetic slips.

Practice tasks reinforce these properties by asking pupils to identify shortcuts and balance equations. Exercises include testing whether a rearrangement is helpful in A handy order of adding: true or false, breaking longer problems down in Four terms, two convenient pairs, and finding hidden values in What is missing on the other side to make it equal.

In Year 3, children learn to measure and calculate the perimeter of simple 2-D shapes. Because a square has four equal sides, children find the perimeter either by adding all four side lengths together or by multiplying one side length by 4, drawing on their 4 times table. They also apply this relationship in reverse to work out the length of a single side when given the total perimeter.

A common error is adding only the two labelled sides of a diagram, forgetting that perimeter requires the full boundary around all four edges. Children also frequently confuse perimeter with area, accidentally multiplying a side by itself rather than multiplying by 4, or dividing a given perimeter by 2 instead of 4 when working backwards.

Typical practice tasks start visually with squares drawn on a grid, moving on to shapes labelled with whole-number measurements. Activities include multiple-choice calculations, true-or-false challenges, finding the difference between two perimeters, and "fix the mistake" exercises where children identify and correct common calculation errors.

In Year 3, children learn to read and write Roman numerals from I to XII (1 to 12). This knowledge is specifically tied to reading analogue clocks that feature Roman numerals instead of standard digits, requiring pupils to connect values to the key symbols I, V (5), and X (10).

A frequent difficulty is mastering subtractive notation, particularly mixing up pairs like IV (4) and VI (6), or IX (9) and XI (11). Children often assume numbers are always formed by adding values together, leading them to misread IV as six or attempt to write four as IIII.

Practice activities focus on building familiarity with these twelve values through varied worksheet tasks. Children put Roman numerals in order from smallest to largest, choose the correct numeral representation, test their knowledge with true-or-false questions, spot and correct reading mistakes, and solve simple addition problems written in Roman numerals.

In Year 3, children move beyond simple counting to extract numbers from tables and scaled bar charts. They answer one-step and two-step questions using this data, working to find totals, identify which category has the most or least, and calculate comparisons such as "how many more" or "how many fewer".

A common mistake occurs when children misinterpret comparison questions. When asked how many more items one category has than another, they often simply read off the total for the larger category rather than subtracting to find the difference between the two values. Errors also happen when children overlook the scale on a bar chart axis, mistakenly reading each interval as one unit instead of checking the scale steps.

Practice tasks present data in a clear table or bar chart and ask children to analyse the quantities. Typical tasks include:

• Finding the difference between two rows and deciding if a comparison statement is true or false.
• Calculating the gap between the largest and the smallest category.
• Identifying which category has the most items or counting how many groups are above a given number.

In Year 3, children learn to measure the perimeter of simple 2-D shapes. For rectangles, they find the total distance around the outside by adding all four side lengths together, or by counting unit segments around the boundary of shapes drawn on a grid.

A common error is adding only the two labeled sides—the length and the width—and forgetting the opposite two sides needed to travel all the way around the shape. Children also frequently count the square units inside the shape rather than tracing the outer edges.

Practice tasks range from calculating the perimeter on a grid to choosing the correct total from multiple options. Children also compare two shapes to decide which figure has the greater perimeter, evaluate whether a given measurement is correct, work out a missing side length from a known total, or draw a rectangle to match a specific perimeter.

In Year 3, children work with three-digit numbers to understand what each digit represents based on its position. They learn to recognise the place value of the hundreds, tens, and ones digits, working with quantities up to 1000. They also learn how to recombine these parts, seeing numbers as collections of hundreds, tens, and ones or as a set of hundreds alongside the remaining amount.

A common error occurs when children confuse a digit's name with its actual value. For example, in the number 472, a child might state that the 7 is worth 7 rather than 70. Another frequent difficulty is telling the difference between the digit in the tens place and the total number of whole tens inside the entire number, such as overlooking that 230 contains 23 whole tens.

Practice tasks build this understanding using both visual models and direct problem-solving. Children read numbers shown as base-ten blocks, build three-digit numbers from separated hundreds, tens, and ones, and split numbers into hundreds and the rest. Other activities challenge them to determine how many whole tens or total ones are in a number and evaluate whether place-value statements are true or false.

In Year 3, children build on earlier addition and subtraction facts to work with numbers up to 1000. They learn to calculate with full hundreds and three-digit numbers mentally, such as finding 354 + 200 or 681 - 300. At this stage, children recognize that adding or taking away hundreds alters only the hundreds column, leaving the tens and ones intact.

A common mistake occurs when children confuse place value columns. For instance, when calculating 245 + 300, a child might mistakenly add the 3 to the tens place instead of the hundreds place, arriving at 275 instead of 545. Children may also accidentally alter the tens or ones digits when subtracting multiples of one hundred.

Tasks on printable worksheets reinforce these steps through varied practice. Children might complete number sequences by jumping by full hundreds, sometimes taking two jumps in a row, or solve equations to identify how many hundreds were added. Other tasks ask children to choose the correct result, find a missing amount to make both sides of an equation balance, or spot and fix the mistake in a completed calculation.

In Year 3, children move from mental calculations to formal written methods, setting out calculations vertically in columns. They work with numbers up to three digits (within 1000), learning to add two or three numbers together and carry out column subtraction with regrouping across place value columns.

A common mistake occurs when children lose track of place value alignment, especially when mixing two- and three-digit numbers. In subtraction, children often reverse digits when the top digit is smaller than the bottom digit—such as calculating 3 minus 7 as 4—instead of exchanging from the next column.

Practice tasks guide children through these formal layouts in several ways:

• Working through column addition step by step or adding three numbers in vertical columns.
• Solving written subtractions within 1000 and choosing the correct result from multiple options.
• Finding missing addends in partially completed addition grids.
• Spotting and correcting mistakes in pre-worked column subtractions.

In Year 3, children build on basic number bonds to work with numbers up to 1000, using the inverse relationship between operations to verify their calculations. They learn that addition and subtraction undo each other, and they apply this logic to multiplication and division. Instead of simply recalculating a problem the same way, pupils learn to reverse the steps to confirm their work or uncover an unknown starting quantity.

A frequent mistake happens when setting up a check for subtraction. Instead of adding the difference to the subtracted amount to see if it restores the original total, children often subtract again or mix up the parts—for example, attempting to subtract the original total from the answer. With multiplication and division, pupils often repeat the original operation rather than inverting it, missing calculation errors entirely.

Practice tasks guide children through applying these relationships directly:

• Checking addition and subtraction: pupils complete prompts like Check a subtraction by adding or evaluate existing work in Is the check of the subtraction right? and Correct the mistake in checking a subtraction.
• Finding missing values: exercises such as What number was it subtracted from? and How many were there before sharing require children to reverse the process to find the initial amount.

In Year 3, children learn that perimeter is the boundary distance around a 2-D shape. For triangles, they calculate this boundary by adding the three side lengths together using addition within 1000. They also work in reverse using subtraction: when given the total perimeter and two side lengths, they can calculate the unknown third side, or use properties of an isosceles triangle to work out the length of its equal legs.

A common mistake occurs when children work with isosceles triangles. Because diagrams often label only one of the equal sides, children frequently add just two numbers together and forget that the matching side must also be included in the total. Another frequent error happens in missing-side problems, where children accidentally add the known sides to the perimeter rather than subtracting them from the total.

Practice tasks provide varied formats using clear diagrams. Children find the total distance in Perimeter of a triangle, decide whether given measurements are accurate in Perimeter of a triangle: true or false, or select solutions in choose the correct answer tasks. They also tackle inverse problems like finding the Third side of a triangle, calculating How long is the leg of an isosceles triangle, and comparing shapes to determine How much larger one triangle's perimeter is than the other's.

In Year 3, children extend place value to numbers up to 1000. They learn to compare two or more three-digit quantities, identify which number is the greatest, and arrange mixed sets in order starting from the least. They also use relation signs (<, >, and =) and calculate the numerical difference to state exactly how much greater one value is than another.

A common mistake occurs when children look at the wrong digits first, focusing on the ones or tens rather than the hundreds. For instance, a child might mistakenly think 389 is larger than 412 because 89 is greater than 12. Errors also arise when numbers have matching hundreds digits (such as 645 and 672), where learners must look systematically to the tens column to decide which is larger.

Worksheet tasks typically present pairs of values where children insert the correct relation sign or answer true-or-false questions about which quantity has more. Other exercises ask children to select the greatest number from a set, order numbers from least to greatest, or calculate how many more are needed to match a larger total within 1000.

In Year 3, children build on measuring in metres and centimetres by introducing millimetres. Working with numbers up to 1000, they accurately measure lengths using a ruler and learn how standard units relate to one another. They practice converting compound lengths, such as metres and centimetres into total centimetres, as well as centimetres and millimetres into millimetres.

A common mistake occurs when children align an object with the physical end of the ruler rather than the zero mark, leading to readings that are off by several millimetres. When converting, children also frequently confuse the place value scales, mistakenly assuming there are 100 millimetres in a centimetre instead of 10, or forgetting to multiply metres by 100 when converting to centimetres.

Worksheet tasks give children practice reading lengths directly from a ruler scale and completing conversion problems. Children answer multiple-choice and true-or-false questions comparing millimetres and centimetres, and they tackle "fix the mistake" exercises to spot and correct incorrect conversions between metres and centimetres.

In Year 3, children solve practical word problems using addition and subtraction with numbers up to 1000. They learn to interpret a short scenario, decide which calculation is needed, and apply mental or written methods to find the solution. This includes working with missing number problems where an initial quantity is unknown, requiring them to figure out how many items were present before a change took place.

A frequent mistake happens when children simply pluck all the numbers from the text and add them together without following the story. When a problem includes extra, irrelevant details, pupils often assume every number must be part of the calculation. Children also struggle when working backwards: seeing a word like "gave away" might prompt them to subtract automatically, even when finding the starting total requires addition.

Tasks give children focused practice with these scenarios. Pupils may be asked which operation solves the problem to find a total altogether, or work out how many are left when an extra number has been included in the text. Other activities focus specifically on calculating how many were there at the start or selecting the correct final answer from multiple options.

In Year 3, children expand their number skills up to 1000, learning to read and write any three-digit number using both digits and words. They learn to link the spoken or written name, such as "four hundred and seventy-two", directly to its numeral form, 472.

A frequent error happens when a number has a zero in the middle, such as "six hundred and five". Children often write what they hear by joining the hundreds and ones together, writing 6005 instead of 605 because they overlook the zero needed as a placeholder in the tens column.

Practice tasks ask children to translate between words and digits, such as writing a spoken number in digits or reading written number words. Children also review completed examples to spot mistakes, choose the correct way of writing a number in digits, or fix numbers where a zero in the middle has been missed.

In Year 3, children work with numbers up to 1000 and learn to approximate answers to addition and subtraction problems by rounding to the nearest ten. Instead of working out precise figures straight away, they learn to make quick mental estimates for real-life situations, particularly when managing money and totals.

A common mistake is calculating the exact answer with column addition or subtraction first, and then rounding the final figure. Children often do this because they distrust rough answers, missing the point that rounding beforehand is meant to make mental arithmetic quicker and simpler. In shopping problems, children also frequently round down according to standard rounding rules, forgetting that estimating costs to see if you have enough money often requires rounding up.

Practice tasks place calculations in clear everyday contexts. Worksheets include exercises such as Estimate the sum: round to the nearest ten and Estimate the difference: round to the nearest ten, where children rewrite calculations using friendlier numbers. Applied activities like About how much will we pay in total, Estimating a cost by rounding up, and Find prices that match the estimate prompt children to test whether purchases fit within a given budget.

In Year 3, children build confidence with addition within 1000. They learn to add single-digit ones or tens to three-digit numbers, such as calculating 342 + 5 or 342 + 30. They also progress to adding full three-digit numbers together and adding sets of three terms, focusing on tasks where no regrouping is required.

A frequent error occurs when children lose track of place value columns during mental addition. For instance, when adding 40 to 523, a child may mistakenly add the 4 to the hundreds column instead of the tens column, giving an answer of 923 instead of 563. When adding three numbers at once, children can also make simple counting slips as they hold partial sums in their heads.

Practice worksheets reinforce these skills through several task types:

• Judging whether a completed addition within 1000 is true or false, or spotting and correcting someone else's mistake.
• Selecting the correct answer from multiple choices or working out the sum of three terms.
• Calculating sums of three-digit numbers with no regrouping, or working backwards to invent two numbers that add up to a given total.

In Year 3, children progress from reading clocks to five-minute intervals to reading time to the nearest minute. They read and write time on analogue clocks with numbers from 1 to 12 as well as dials featuring Roman numerals from I to XII. Children also work with 12-hour and 24-hour time, using terms such as a.m., p.m., noon, and midnight while comparing times in hours, minutes, and seconds.

A frequent error happens when the minute hand is approaching the next hour (for example, at 8:50). Because the short hour hand sits very close to the 9, children often mistakenly read the time as 9:50 instead of 8:50. Confusing similar Roman numerals—such as reading IV (4) as VI (6)—is another common reason for misreading a dial.

Worksheets give children targeted practice through tasks such as identifying which time is on a dial, deciding if a stated time is true or false, and finding and correcting mistakes on clock faces. Other activities prompt them to calculate how many minutes remain until the full hour or compare two clock faces to decide which shows the earlier time.

In Year 3, children measure, compare, add, and subtract capacities using standard units of litres (l) and millilitres (ml), working with numbers up to 1000. They build on earlier measuring skills to solve practical problems, such as finding how much liquid is needed to fill a container or calculating total volume when combining whole and half-litre amounts.

A common mistake occurs when children focus only on the numerals and ignore the units. For example, a child might assume that 500 ml is more than 1 l because 500 is greater than 1. Children also stumble when grouping smaller containers, such as forgetting that two half-litre bottles are required to make one whole litre.

Practice tasks focus on concrete, real-world calculations:

• Calculating how many more to fill it when given a container's target capacity and its current level.
• Finding how much more one container holds than the other using subtraction.
• Determining how many litres from that many half-litre bottles or working out how many bottles will the juice fill.
• Evaluating true-or-false statements comparing different volumes of liquid.

In Year 3, children extend their counting skills across numbers up to 1000. They build confidence counting forwards from 0 in multiples of 4, 8, 50, and 100, as well as counting backwards in these same equal jumps. They also learn to shift quickly along the number line by finding 10 or 100 more or less than any starting number.

A frequent stumbling block occurs when counting across hundreds boundaries, such as stepping forwards from 350 to 400 or backwards past a multiple of 100. Children also commonly mix up place values when finding 10 or 100 more or less—for example, changing the tens column instead of the hundreds column when subtracting 100 from a number like 420.

Practice tasks reinforce these patterns through a variety of formats. Children may complete a sequence where they keep counting by the same step or count backwards in equal steps. Other activities ask them to choose the next number, spot and correct the wrong number hidden in a sequence, or calculate how many times you must count on to get there.

In Year 3, children build on their 2 times table to calculate products of a two-digit number multiplied by 2. They learn to break numbers into tens and ones to double them mentally, while also beginning to record their steps using formal written methods.

A common mistake occurs when doubling numbers with ones digits of 5 or greater, such as 36. Children often double the tens (30 becomes 60) and double the ones (6 becomes 12), but then forget to combine the extra ten, arriving at an answer like 612 or 62 instead of 72.

Practice activities focus on building accuracy with quick calculations. Children work through tasks such as:

• calculating direct multiplications and choosing the correct result from multiple options;
• evaluating true-or-false statements about doubled numbers;
• working backwards to determine which number doubled gives a specific total;
• comparing values to find how much more remains after doubling both numbers.

In Year 3, children work with lengths up to 1000 using metres, centimetres, and millimetres. They learn to interpret measurements presented in mixed formats—such as metres and centimetres together—and understand how to switch between different notations, such as finding how many whole metres are in a measurement.

A common mistake is adding the numbers directly without converting the units first. For example, a child calculating the total of 1 m and 20 cm might simply add the values to get 21, mistakenly writing 21 m or 21 cm because they overlook that metres and centimetres represent different scales.

Practice tasks ask children to look at two length notations together to choose the correct answer or decide if a statement is true or false. They also solve addition questions using different notations and calculate how much longer one measurement is than another.

In Year 3, children learn to describe the direction of straight lines. They recognise horizontal lines as running level from side to side (like the horizon), vertical lines as standing straight up and down, and oblique lines as lines that slant at an angle. Children learn to identify these orientations in diagrams and draw them accurately.

A common mistake is confusing the terms horizontal and vertical, mixing up which label belongs to which direction. Children also sometimes overlook slight tilts; if an oblique line is steep, they may incorrectly label it as vertical because it looks mostly upright, rather than noticing that it is slanted.

Practice tasks reinforce these definitions through varied formats. Children identify line types using tasks like Vertical, horizontal or oblique and What kind of line is it? Choose, evaluate labeled diagrams in Vertical, horizontal or oblique? True or false, fix mislabeled examples in Correct it, and use a ruler in Draw a line: vertical, horizontal or oblique.

In Year 3, children work with data presented in tables and pictograms, working with quantities within numbers up to 1000. They read values directly from rows and columns, add entries together to find an overall total, and work backwards to work out a missing row when the grand total is already known. They also read pictograms where a single symbol represents more than one item.

A common mistake occurs when reading pictograms where one picture stands for several objects. Children often count each symbol as one instead of checking the key and multiplying or counting in steps. In tables, errors happen when children accidentally skip a row or miscalculate when finding the sum of several values.

Typical tasks ask children to find how many there are altogether in a table or verify a total through true-or-false and multiple-choice questions. Children also solve problems where they must work out the value of a missing row when the total is known, or read pictograms where each picture represents a group of items.

In Year 3, children build confidence measuring, comparing, adding, and subtracting mass using standard units such as kilograms (kg) and grams (g). Working with numbers up to 1000, they develop a sense of scale for everyday items and learn to work out how many smaller parts or portions are contained within a given package.

A common difficulty arises when bridging to a whole unit. When calculating how much mass is missing to complete a full kilogram, children often subtract from 100 rather than 1000, confusing tens and hundreds with standard metric conversions. They may also make calculation errors when scaling between larger mass units and smaller subunits.

Practice tasks reinforce these relationships through targeted problem types:

• Deciding whether statements converting kilograms to decagrams are true or false, or choosing the correct converted value from a multiple-choice list.
• Calculating how much mass is missing to make a full kilogram from a given starting amount.
• Solving practical sharing tasks to determine how many equal portions a single package makes.

In Year 3, children build on reading clock faces by calculating time intervals and converting between units. Knowing that there are 60 seconds in a minute, they convert mixed times—such as 1 minute and 20 seconds—into total seconds. They also calculate elapsed time, working out how many hours and minutes have passed between a start time and an end time.

A common mistake is treating time like standard base-10 arithmetic. Because children are used to working in tens and hundreds, they often assume there are 100 minutes in an hour or 100 seconds in a minute. When calculating elapsed time across the hour—such as from 1:50 to 2:10—they may incorrectly count 60 minutes instead of bridging through the 60-minute mark to find the correct 20-minute duration.

Worksheets for this skill feature three specific task formats:

• Minutes and seconds to seconds, where children convert mixed time amounts into a single number of seconds.
• How many minutes have passed?, which shows pairs of clock times and asks for the difference in minutes.
• How long did it last?, requiring children to work out the total duration of an activity from its start and end times.

In Year 3, children learn to add and subtract fractions that share the same denominator (the bottom number), keeping calculations within one whole. For example, they solve problems such as 5/7 + 1/7 = 6/7 or subtract parts of a whole, such as 4/6 - 3/6 = 1/6.

The most common mistake is adding or subtracting the denominators as well as the numerators—such as calculating 1/5 + 2/5 and writing 3/10. This happens because children naturally try to apply whole-number addition across both lines, not yet realising that the denominator simply names the size of the equal parts rather than an amount being counted.

Practice in this area uses targeted worksheets based on two templates: Add fractions with like denominators and Subtract fractions with like denominators. These tasks give children straightforward number sentences where the denominator remains constant, helping them build fluency in combining and taking away parts of a whole.

In Year 3, children solve practical word problems using numbers up to 1000. Building on place value and column addition methods, they read a written scenario, identify which quantities need to be combined, and carry out two sequential calculations to find an overall total.

A common mistake is stopping after the first step. When a problem involves combining several amounts, children often perform one addition, find an intermediate total, and assume the task is finished without adding the remaining quantity to complete the problem.

Worksheet tasks use the Two-step word problem (combine) template. In these exercises, pupils read a short story context—such as adding quantities of items collected across three classes or calculating the total weight of several parcels—and write out the two addition steps needed to reach the final answer.

In Year 3, children recognise an angle as a property of a shape or a description of a turn. Using a quarter-turn as a reference, they learn to spot right angles and classify any other angle based on whether it is greater than or less than a right angle. They also connect right angles to fractions of a turn, recognising that two right angles make a half-turn, three make three-quarters of a turn, and four make a complete turn.

A common mistake is judging the size of an angle by the length of its drawn lines rather than the amount of spread between them. Children frequently believe an angle with long lines is larger than a right angle drawn with short lines, or they struggle to recognise a right angle when it is tilted away from horizontal and vertical alignments.

Worksheet tasks from the Classify the angle template present drawn angles in different orientations. Children inspect each corner and determine whether it represents a right angle, an angle smaller than a right angle, or one greater than a right angle, often checking by fitting a square corner against the vertex.

In Year 3, children learn to calculate unit fractions (such as 1/3, 1/4, or 1/8) and non-unit fractions (such as 2/3 or 3/4) of a set of objects or a number. They connect this to their times tables, sharing a quantity into equal groups using the denominator and then counting the required number of parts using the numerator.

A common mistake occurs when moving from unit to non-unit fractions. For example, when finding 3/4 of 20, a child might correctly divide 20 by 4 to get 5, but stop there and write 5 as the final answer, forgetting to multiply by the numerator 3. Children also occasionally mix up the roles of the digits, dividing by the top number instead of the bottom number.

Tasks using the Find a fraction of a number template give children straightforward practice with these calculations, presenting questions such as finding 1/3 of 24 or 3/8 of 16. Children apply their division and multiplication facts to work through the steps and write the whole number result.

Children use their known times tables—such as the 3, 4, and 8 times tables—to multiply a single-digit number by a two-digit multiple of 10, finding answers to calculations such as 3 × 40 or 8 × 20. They learn to see 3 × 40 as 3 groups of 4 tens, using the related fact 3 × 4 = 12 to determine that the total is 12 tens, or 120.

A typical error happens when children rely on a mechanical rule of "just adding a zero" without understanding place value. This can cause children to confuse addition and multiplication—such as calculating 3 × 4 = 12 and then adding 10 to get 22—or to misapply basic multiplication facts before adjusting the number into tens.

In tasks based on the Multiply by a multiple of ten template, children solve calculation statements such as 4 × 30 = ___ or 70 × 3 = ___. These exercises provide structured practice that connects quick mental recall of single-digit multiplication directly to working with tens.

In Year 3, children build confidence with fractions by comparing those that share the same denominator. Using diagrams with small denominators, they learn that when a shape or quantity is split into equal-sized parts, the fraction with the larger numerator represents more of those parts.

A common mistake occurs when children lose track of what each number represents. Because whole-number intuition leads them to expect larger numbers to always mean more, they can get confused about whether to look at the numerator or the denominator, especially if they have not yet visualised the parts as slices of the same whole.

Worksheets for this skill focus on tasks to compare fractions with the same denominator. Children are presented with pairs of fractions, such as 2/6 and 5/6, and use comparison symbols or visual bar models to determine which fraction is greater.

In Year 3, children learn to recognise and use fractions as numbers, working with unit fractions (such as 1/3 or 1/4) and non-unit fractions (such as 2/3 or 3/4) with small denominators. Rather than only splitting shapes, they apply fractions to amounts to find a fraction of a whole quantity.

A common mistake occurs when working with non-unit fractions. Children often divide by the denominator (the bottom number) to find one equal share, but forget the second step: multiplying that result by the numerator (the top number) to count all the required parts.

In typical tasks using the Fraction of a set: a/b of the whole template, children solve problems such as finding 2/3 of 12 or 3/4 of 20. They divide the total into equal groups based on the bottom number and then combine the correct number of groups indicated by the top number.

In Year 3, children build their understanding of numbers up to 1000 by representing them visually on a number line. At this stage, they learn to locate specific values and navigate along the line by counting in steps of ten, moving both forwards and backwards from different starting points.

A common mistake occurs when children count the tick marks on the line rather than the spaces between them. They often land one step early or late because they treat the starting mark as their first jump of ten instead of measuring the distance moved.

Practice tasks feature number lines where pupils complete the template Jump by tens on the number line. Children trace or draw hops of ten from a given number to find a missing value, helping them link place value with physical distance on the scale.

In Year 3, pupils build on their understanding of dividing quantities into ten equal parts to explore decimal notation. While the national curriculum introduces tenths at this stage, children also begin recognising the place value positions that follow the decimal point, learning to pinpoint both tenths and hundredths.

A common mistake is confusing the tenths and hundredths positions. Children often assume the first digit after the decimal point represents hundredths because the word reminds them of two zeros, or they confuse whole-number hundreds on the left with decimal hundredths on the right. Others read decimals backwards from right to left, mixing up which column holds which value.

Worksheet tasks ask pupils to find the digit in the hundredths place from a given decimal number. For example, when looking at a number like 3.48, the child identifies that 4 is in the tenths place and correctly selects 8 as the digit in the hundredths place.

In Year 3, children learn to look at pairs of straight lines and determine how they relate to one another. At this stage, they identify whether line segments on a squared grid are parallel (running alongside each other in the exact same direction, staying an equal distance apart) or perpendicular (meeting or crossing at a square right angle).

A common error occurs when lines do not visibly touch. Children often assume that two segments cannot be perpendicular unless they cross directly like a plus sign, missing lines that form an "L" shape or segments that would meet at a right angle if extended. Others confuse the two terms entirely, forgetting which word describes lines that never meet and which describes lines that form square corners.

Practice tasks using the Parallel or perpendicular? template show pairs of line segments drawn on a square grid. Children examine the lines and decide whether the pair is parallel, perpendicular, or neither.