Making 1 Whole Using Decimals: Step-by-Step Example
22 October 2026
Understanding how to make 1 whole using decimals is a key skill for 11+ maths. It helps children see how smaller decimal parts can be combined to make a complete number.
Worked example
Question: What do you add to 0.6 to make 1?
Step 1: Start with 0.6.
Step 2: Think, what number plus 0.6 equals 1?
Step 3: Write it as 0.6 +? = 1.
Step 4: Subtract 0.6 from 1. So, 1 - 0.6 = 0.4.
Step 5: Check: 0.6 + 0.4 = 1.
The correct answer is 0.4.
Click or tap on the number line to answer
After working through this example, your child will recognise how to find the missing decimal needed to reach 1. They can now try similar questions to build their confidence with decimals and making a whole.
