Stage 2 · Add & subtract strategies
Adding and subtracting tens
Ones stay put: just add or take the tens.
How to do it
Method
Ones stay put: just add or take the tens
46 + 30 = 76 (4 + 3 = 7)
Another way
Columns
Ones 6 + 0 = 6, tens 4 + 3 = 7 → 76
In full
When you add or subtract whole tens the ones digit never moves — you're just doing a single-digit sum in the tens place. 46 + 30 → 4+3=7 → 76. If the tens reach ten, they carry into the hundreds: 89 + 80 → 8+8=16 → 169. You can also line the digits up in columns; it's the same idea.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
28 − 20
Show the answer and working
Answer: 28 − 20 = 8
The ones (8) stay put; just the tens: 2 − 2 = 0 → 8
Example 2
81 + 10
Show the answer and working
Answer: 81 + 10 = 91
The ones (1) stay put; just the tens: 8 + 1 = 9 → 91
Example 3
83 + 40
Show the answer and working
Answer: 83 + 40 = 123
The ones (3) stay put; just the tens: 8 + 4 = 12 → 123
Example 4
45 + 80
Show the answer and working
Answer: 45 + 80 = 125
The ones (5) stay put; just the tens: 4 + 8 = 12 → 125
Practise adding and subtracting tens in the game →Stage 2 · Add & subtract strategies · Free to start, unlimited questions, no download