Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 743 · 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. 1.902 − 447 =
2. 2.877 − 698 =
3. 3.363 − 199 =
4. 4.559 − 149 =
5. 5.624 − 537 =
6. 6.919 − 557 =
7. 7.815 − 457 =
8. 8.926 − 499 =
9. 9.827 − 699 =
10. 10.513 − 299 =
11. 11.816 − 597 =
12. 12.872 − 597 =
13. 13.750 − 497 =
14. 14.739 − 627 =
15. 15.221 − 198 =
16. 16.488 − 258 =
17. 17.410 − 137 =
18. 18.708 − 599 =
19. 19.578 − 198 =
20. 20.463 − 397 =
21. 21.961 − 188 =
22. 22.886 − 798 =
23. 23.387 − 338 =
24. 24.873 − 297 =
25. 25.743 − 599 =
26. 26.661 − 228 =
27. 27.838 − 669 =
28. 28.570 − 297 =
29. 29.843 − 799 =
30. 30.666 − 597 =
31. 31.386 − 127 =
32. 32.778 − 597 =
33. 33.215 − 127 =
34. 34.416 − 189 =
35. 35.900 − 298 =
36. 36.851 − 509 =
37. 37.556 − 299 =
38. 38.690 − 659 =
39. 39.736 − 668 =
40. 40.214 − 197 =

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