Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 699 · 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. 1.546 − 379 =
2. 2.787 − 498 =
3. 3.898 − 798 =
4. 4.419 − 328 =
5. 5.600 − 439 =
6. 6.625 − 599 =
7. 7.937 − 698 =
8. 8.797 − 547 =
9. 9.762 − 697 =
10. 10.889 − 378 =
11. 11.926 − 598 =
12. 12.666 − 629 =
13. 13.900 − 699 =
14. 14.977 − 397 =
15. 15.287 − 197 =
16. 16.965 − 497 =
17. 17.643 − 298 =
18. 18.976 − 497 =
19. 19.568 − 518 =
20. 20.486 − 398 =
21. 21.969 − 799 =
22. 22.947 − 569 =
23. 23.655 − 597 =
24. 24.916 − 298 =
25. 25.802 − 699 =
26. 26.843 − 797 =
27. 27.986 − 598 =
28. 28.976 − 697 =
29. 29.923 − 399 =
30. 30.700 − 658 =
31. 31.530 − 439 =
32. 32.469 − 369 =
33. 33.861 − 497 =
34. 34.858 − 497 =
35. 35.488 − 197 =
36. 36.231 − 199 =
37. 37.822 − 799 =
38. 38.813 − 499 =
39. 39.549 − 347 =
40. 40.366 − 317 =

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