Adding full tens
Adding full tens helps children practise adding full tens by treating them like single digits: 30 + 40 = 7 tens = 70. Read the short guide and look through the examples before choosing online practice or a printable worksheet.
How to solve this
- When adding a full ten to a number, only the tens digit changes — the ones digit stays the same.
- Split the addition: add the tens part first, then bring the ones digit across unchanged.
- Check by working backwards: subtract the ten you added and you should get the original number.
Examples
30 + 20 = ?
50
60 + 10 = ?
70