Making a whole with decimals for 11+ maths
21 October 2026
Why making a whole matters
Understanding how to make a whole number using decimals is an important skill for the 11+ exam. This helps children work confidently with money, measurements and fractions in real life and in test questions.
Worked example
Start with 0.4. This is the same as 4 tenths.
Add 0.3. 0.4 + 0.3 = 0.7
Add 0.2. 0.7 + 0.2 = 0.9
You need 0.1 more to reach a whole.
Add 0.1. 0.9 + 0.1 = 1.0
The correct answer is 1.0.
Why this skill is useful
Questions about making a whole with decimals often appear in 11+ maths. Practising this helps children spot missing parts and build confidence when working with decimal numbers.
Key insight: Understanding how decimals combine to make a whole is a foundation for many topics in maths, including money, measures and fractions.
