How to explain ordering decimals in missing digits, compare & challenge to your student
27 October 2026
When decimals have missing digits, it can be tricky to put them in order. The key is to compare each number carefully, making sure you look at the value of each digit and fill in any gaps logically.
Worked example
Put these decimals in order from smallest to largest:
3.4_ 3._8 3.42
Step 1: Write the numbers so the decimal points line up: 3.4_ 3._8 3.42
Step 2: Add zeros if it helps you see the place value: 3.4_0 3.08 3.42
Step 3: Fill in the missing digits so each number could be the smallest possible:
3.40 3.08 3.42
Step 4: Now compare the numbers:
3.08 is the smallest.
Then 3.40.
Then 3.42.
So the order is: 3._8, 3.4_, 3.42
The correct answer is:
3._8, 3.4_, 3.42 (smallest to largest).
| Decimal | Missing digit filled | Value |
|---|---|---|
| 3.4_ | 3.40 | 3.40 |
| 3._8 | 3.08 | 3.08 |
| 3.42 | 3.42 | 3.42 |
After working through this example, your child will recognise how to spot the smallest and largest decimals, even when some digits are missing. They can now try more questions like this to build confidence with ordering decimals in missing digits, compare & challenge to your student.
