Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 284 · 40 questions

How to do it in your head (Round up, add back): Round the number you take away up to the next ten or hundred: 297 → 300 (3 too many). Take away the round number. Add back the extra, because you took away too much.

1. 1.810 − 697 =
2. 2.233 − 119 =
3. 3.494 − 197 =
4. 4.612 − 499 =
5. 5.997 − 798 =
6. 6.662 − 119 =
7. 7.780 − 617 =
8. 8.938 − 698 =
9. 9.669 − 579 =
10. 10.692 − 128 =
11. 11.613 − 508 =
12. 12.339 − 199 =
13. 13.380 − 198 =
14. 14.898 − 639 =
15. 15.780 − 577 =
16. 16.797 − 639 =
17. 17.545 − 199 =
18. 18.403 − 239 =
19. 19.574 − 198 =
20. 20.672 − 449 =
21. 21.942 − 797 =
22. 22.457 − 397 =
23. 23.395 − 317 =
24. 24.825 − 517 =
25. 25.603 − 247 =
26. 26.718 − 698 =
27. 27.506 − 128 =
28. 28.708 − 197 =
29. 29.869 − 499 =
30. 30.419 − 399 =
31. 31.875 − 397 =
32. 32.329 − 309 =
33. 33.600 − 497 =
34. 34.994 − 127 =
35. 35.649 − 349 =
36. 36.811 − 699 =
37. 37.772 − 549 =
38. 38.456 − 237 =
39. 39.886 − 799 =
40. 40.445 − 408 =

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