Two-digit adding and taking away · Usually met around P1
Two-digit addition with regrouping
Left to right: tens first, then ones.
How to do it
Method
Left to right: tens first, then ones
47 + 38 = 47 + 30 + 8 = 77 + 8 = 85
Another way
Column addition
Ones 7 + 8 = 15, write 5, carry 1; tens 4 + 3 + 1 = 8 → 85
In full
Work from left to right. 47 + 38 → tens first, 47+30=77, then ones, 77+8=85. Column addition starts from the ones and gets the same answer. In your head, start with the big end, because that's the part you say first.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
71 + 19
Show the answer and working
Answer: 71 + 19 = 90
Left to right, add the tens first: 71 + 10 = 81, then the ones: 81 + 9 = 90
Example 2
52 + 18
Show the answer and working
Answer: 52 + 18 = 70
Left to right, add the tens first: 52 + 10 = 62, then the ones: 62 + 8 = 70
Example 3
63 + 23
Show the answer and working
Answer: 63 + 23 = 86
Left to right, add the tens first: 63 + 20 = 83, then the ones: 83 + 3 = 86
Practise it in the game →Two-digit adding and taking away · Free to start, unlimited questions, no download