Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 327 · 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. 1.396 − 377 =
2. 2.877 − 499 =
3. 3.552 − 127 =
4. 4.433 − 189 =
5. 5.776 − 417 =
6. 6.914 − 198 =
7. 7.891 − 247 =
8. 8.968 − 377 =
9. 9.804 − 199 =
10. 10.862 − 268 =
11. 11.963 − 697 =
12. 12.536 − 518 =
13. 13.649 − 298 =
14. 14.566 − 399 =
15. 15.480 − 377 =
16. 16.886 − 197 =
17. 17.722 − 159 =
18. 18.451 − 299 =
19. 19.521 − 497 =
20. 20.307 − 199 =
21. 21.606 − 399 =
22. 22.512 − 299 =
23. 23.417 − 297 =
24. 24.635 − 308 =
25. 25.635 − 399 =
26. 26.789 − 298 =
27. 27.846 − 397 =
28. 28.611 − 397 =
29. 29.993 − 607 =
30. 30.801 − 199 =
31. 31.841 − 407 =
32. 32.901 − 199 =
33. 33.715 − 599 =
34. 34.631 − 498 =
35. 35.718 − 499 =
36. 36.723 − 597 =
37. 37.772 − 207 =
38. 38.596 − 407 =
39. 39.710 − 379 =
40. 40.569 − 498 =

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