Add a two-digit number to a three-digit number: step-by-step example
30 October 2026
When your child is learning to add larger numbers, it helps to see the method set out clearly. Written addition is a reliable way to combine a two-digit number with a three-digit number, step by step.
Example question
Add 247 + 58 using written addition.
Write the numbers in columns, lining up the digits by place value:
247 + 58
Start with the ones column: 7 + 8 = 15. Write 5 in the ones place and carry over 1 to the tens column.
Add the tens column: 4 + 5 = 9. Add the carried over 1 to get 10. Write 0 in the tens place and carry over 1 to the hundreds column.
Add the hundreds column: 2 + 0 = 2. Add the carried over 1 to get 3. Write 3 in the hundreds place.
The answer is 305.
| Step | Working | Carry Over | Result Digit |
|---|---|---|---|
| Ones | 7 + 8 = 15 | 1 | 5 |
| Tens | 4 + 5 + 1 = 10 | 1 | 0 |
| Hundreds | 2 + 0 + 1 = 3 | 3 |
Key insight: After working through this example, your child will spot how each column is handled, including carrying over. This builds confidence for tackling similar questions in written addition and subtraction.
