Year 1 Addition and Subtraction Worksheets

While Year 1 pupils focus on reading and writing subtraction statements up to 20 using the – and = signs, this skill stretches their learning towards working with two-digit numbers up to 100. Children calculate how many are left after taking an amount away, work through subtractions step by step, and figure out an unknown starting amount.

A common difficulty arises when counting backwards across a tens boundary on a hundred grid. For instance, when subtracting past a multiple of ten like 40, a child might jump back to 49 instead of 39 because they lose track of the row change. Children also mix up addition and subtraction when tackling word problems that involve both items leaving and new ones arriving.

Worksheet tasks build confidence through structured visual formats and reasoning challenges, including:

• Jumping back on the hundred grid to solve calculations step by step.
• Two subtractions in a row and identifying how many were there at the start.
• Spotting errors by checking someone else's result and finding the mistake.
• Filtering extra details in tasks that feature one number too many.

In Year 1, children solve one-step addition and subtraction problems within 20 where one value is replaced by an empty box. Using concrete counters and pictures, they work out missing values in different positions, including missing addends and equations where the total comes first, such as 7 = □ – 9.

A common error occurs when children treat the equals sign as a command to calculate rather than a sign of balance. When seeing an equation like 4 + □ = 10 or 5 = □ – 3, children often add the two visible numbers together and write 14 or 8 in the box, not realising that the two sides must have the same total value.

Worksheet tasks make this relationship visual and concrete. Typical activities include:

• using a balanced scale to figure out how much a hidden block weighs;
• finding how many more counters are needed to make both sides equal;
• working out which number hides in the box for addition and subtraction;
• finding a missing number in a sum of three numbers or filling in two boxes in turn.

In Year 1, children learn to read and write addition sentences using the plus (+) and equals (=) signs. They work with numbers up to 20, adding one-digit numbers to two-digit numbers (such as 13 + 4) as well as adding zero. At this stage, calculations do not require regrouping, meaning the ones do not add up to ten or more, keeping the tens digit steady.

A frequent difficulty is counting all items from one rather than counting on from the larger number. When faced with 12 + 3, a child might recount from 1 all the way to 15, which often leads to miscounts. Another common error is confusing the tens and ones places, leading children to add to the tens digit instead of the ones.

Worksheet tasks make these sums visual and varied. Children might:

• Use double ten frames to place counters and see how tens and ones combine.
• Solve true-or-false questions or correct given mistakes in equations.
• Choose the correct sum from multiple-choice options, find what is missing to make ten, or add three small numbers that total up to 20.

At this stage, children work with numbers within 20 to connect addition and subtraction facts. They use their knowledge of number bonds to understand that these operations reverse each other—recognising that if two numbers add up to a total, subtracting one part leaves the other.

A common error happens when children try to check a subtraction. Instead of adding the parts back together to find the original whole, they often subtract again or confuse which number was the starting amount, leading to an impossible statement.

Worksheet activities reinforce these links through targeted exercises, including:

• Checking an addition by subtraction, or checking a subtraction by adding.
• Reviewing completed calculations in tasks like Is the check of the subtraction right? and Correct the mistake in checking a subtraction.
• Finding the missing total in multiple-choice questions such as What number was it subtracted from? Choose.

In Year 1, children solve one-step addition and subtraction word problems using numbers up to 20. At this stage, they rely on concrete objects and pictorial representations to visualise the situation, helping them combine amounts or calculate how many are left.

A common mistake is plucking the numbers out of the sentence and automatically adding them together without understanding what is happening in the story. Children also frequently get confused when given extra details that are not needed to solve the question, or when they need to work backwards to find a missing starting number.

Worksheet tasks present short illustrated scenarios where children identify which operation solves the problem or work out how many are left. Typical activities include finding how many were there at the start, solving for an amount altogether, and ignoring an extra number to choose the correct result.