Solving missing number calculations for 11+ maths
21 October 2026
Why missing number calculations matter
Missing number calculations are a regular feature in 11+ maths exams. These questions help children develop strong problem-solving skills and a deeper understanding of how numbers work together.
How these questions work
A missing number question asks your child to find the value that completes a calculation. The missing number could be in an addition, subtraction, multiplication or division problem.
Worked example
7 + __ = 15
Step 1: Look at the sum and find the missing number.
Step 2: Subtract 7 from 15 to find what goes in the blank.
Step 3: 15 - 7 = 8
The correct answer is 8.
Using the opposite operation
To find a missing number, use the opposite operation. For addition, subtract. For subtraction, add. For multiplication, divide. For division, multiply.
Building confidence through practice
Encourage your child to write out each step, even if they think they can do it in their head. Regular, short practice sessions help children feel more confident and make fewer mistakes under exam pressure.
Key insight: Missing number calculations build essential problem-solving skills for 11+ maths and are best mastered through clear, step-by-step practice.
