Inverse and Working Backwards

L.O. To solve calculations by working backwards

1) 8613 + 1378 = 9991

2) 7982 + 4549 = 12531

3) 58.79 + 32.513 = 91.303

4) 5217 - 3504 = 1713

5) 87.29 - 21.34 = 65.95

6) 2148 x 6 = 12 888

7) 1379 x 7 = 9653

8) 326 x 14 = 4564

9) 227 x 25 = 5675

10) 8154 ÷ 6 = 1359

11) a) 85   b) 70

12) 29

13) Any numbers with a difference of 13 e.g. 1 and 14, 2 and 15 etc.

14) 76

15) 80 (1/2 + 1/4 = 3/4   3/4 = 60   1/4 = 20   4/4 = 80)

16) 124

17) 15