Two-digit adding and taking away · Usually met around P1
Two-digit taking away, no exchanging
Tens, then ones; check by adding.
How to do it
Method
Tens, then ones; check by adding
68 − 25 = 68 − 20 − 5 = 43
Another way
Tens and ones apart
6 − 2 = 4, 8 − 5 = 3 → 43
In full
Taking a two-digit number from another when the ones are enough: take the tens first, then the ones, 68 − 25 → 68 − 20 = 48, 48 − 5 = 43. Or take tens from tens and ones from ones: 6 − 2 = 4 tens, 8 − 5 = 3 ones, together 43. Then check by adding: the answer plus the number taken away must give the number you started with, 43 + 25 = 68. Right.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
79 − 8 = □
Show the answer and working
Answer: 71
Ones 9 − 8 = 1; the tens stay: 71.
Example 2
99 − 60: tens 9 − 6 = □, ones 9 − 0 = □, so the answer is □.
Fill in each box
Show the answer and working
Answer: 3，9，39
3 tens and 9 ones make 39.
Example 3
99 − 63 = 36. Which addition checks it?
- A. 99 − 36 = 63
- B. 36 + 99 = 135
- C. 36 + 63 = 99
- D. 99 + 63 = 162
Choose the right answer
Show the answer and working
Answer: C. 36 + 63 = 99
The answer 36 plus the 63 taken away must give the 99 you started with.
Practise it in the game →Two-digit adding and taking away · Free to start, unlimited questions, no download