Two-digit adding and taking away · Usually met around P1
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 take away whole tens, the ones digit doesn't change at all: you just do a one-digit sum in the tens place. 46 + 30 → 4 + 3 = 7 → 76. Taking away tens works the same way: 76 − 30 → 7 − 3 = 4 → 46. Picture the tens digit moving on its own. Or use columns, ones under ones and tens under tens: the same idea.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
53 − 20
Show the answer and working
Answer: 53 − 20 = 33
The ones (3) stay put; just the tens: 5 − 2 = 3 → 33
Example 2
67 − 30
Show the answer and working
Answer: 67 − 30 = 37
The ones (7) stay put; just the tens: 6 − 3 = 3 → 37
Example 3
82 + 10
Show the answer and working
Answer: 82 + 10 = 92
The ones (2) stay put; just the tens: 8 + 1 = 9 → 92
Practise it in the game →Two-digit adding and taking away · Free to start, unlimited questions, no download