In class, we have been practising the inverse when checking answers. Please try to have a go at some of these at home.
e.g.: 234 – 121 =
Estimate first, by rounding to the nearest 10: 230 – 120 =
230- 100 – 20 = 110
Now do it:
2 3 4
– 1 2 1
1 1 3
Then CHECK it:Use the opposite symbol to the one used in the sum, which would be a +
1 1 3
+ 1 2 1
2 3 4 CORRECT!
Have a go at these:
1) 524 – 231 =
2) 332 – 112 =
3) 987 – 206 =
4) 901 – 432 =
5) 443 + 221 =
6) 201 + 109 =