Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 933 · 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. 1.927 − 798 =
2. 2.854 − 699 =
3. 3.484 − 309 =
4. 4.541 − 339 =
5. 5.921 − 799 =
6. 6.800 − 597 =
7. 7.665 − 597 =
8. 8.803 − 379 =
9. 9.930 − 308 =
10. 10.879 − 698 =
11. 11.785 − 298 =
12. 12.343 − 297 =
13. 13.460 − 138 =
14. 14.383 − 298 =
15. 15.280 − 169 =
16. 16.598 − 537 =
17. 17.948 − 159 =
18. 18.737 − 448 =
19. 19.721 − 497 =
20. 20.600 − 198 =
21. 21.723 − 699 =
22. 22.888 − 199 =
23. 23.800 − 619 =
24. 24.457 − 317 =
25. 25.362 − 197 =
26. 26.728 − 699 =
27. 27.521 − 499 =
28. 28.771 − 597 =
29. 29.635 − 399 =
30. 30.462 − 268 =
31. 31.713 − 299 =
32. 32.700 − 539 =
33. 33.320 − 237 =
34. 34.744 − 397 =
35. 35.626 − 288 =
36. 36.634 − 597 =
37. 37.587 − 459 =
38. 38.436 − 298 =
39. 39.435 − 298 =
40. 40.524 − 398 =

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