Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 985 · 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. 1.679 − 217 =
2. 2.708 − 497 =
3. 3.661 − 599 =
4. 4.941 − 209 =
5. 5.883 − 519 =
6. 6.552 − 489 =
7. 7.536 − 199 =
8. 8.505 − 197 =
9. 9.792 − 657 =
10. 10.376 − 337 =
11. 11.379 − 299 =
12. 12.891 − 499 =
13. 13.867 − 798 =
14. 14.977 − 697 =
15. 15.653 − 498 =
16. 16.797 − 508 =
17. 17.322 − 229 =
18. 18.839 − 698 =
19. 19.838 − 397 =
20. 20.709 − 197 =
21. 21.753 − 297 =
22. 22.534 − 148 =
23. 23.745 − 497 =
24. 24.946 − 397 =
25. 25.817 − 298 =
26. 26.836 − 798 =
27. 27.574 − 179 =
28. 28.703 − 559 =
29. 29.498 − 259 =
30. 30.800 − 598 =
31. 31.942 − 399 =
32. 32.700 − 599 =
33. 33.754 − 398 =
34. 34.730 − 598 =
35. 35.733 − 697 =
36. 36.920 − 199 =
37. 37.955 − 598 =
38. 38.390 − 157 =
39. 39.397 − 198 =
40. 40.621 − 399 =

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