Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 108 · 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. 1.476 − 299 =
2. 2.947 − 197 =
3. 3.898 − 367 =
4. 4.866 − 679 =
5. 5.600 − 199 =
6. 6.720 − 399 =
7. 7.523 − 199 =
8. 8.747 − 289 =
9. 9.345 − 277 =
10. 10.820 − 368 =
11. 11.893 − 279 =
12. 12.649 − 218 =
13. 13.756 − 598 =
14. 14.573 − 219 =
15. 15.428 − 217 =
16. 16.588 − 559 =
17. 17.433 − 398 =
18. 18.952 − 659 =
19. 19.713 − 598 =
20. 20.752 − 637 =
21. 21.967 − 509 =
22. 22.704 − 397 =
23. 23.701 − 647 =
24. 24.384 − 279 =
25. 25.383 − 197 =
26. 26.554 − 187 =
27. 27.340 − 287 =
28. 28.518 − 497 =
29. 29.665 − 337 =
30. 30.764 − 197 =
31. 31.931 − 699 =
32. 32.951 − 697 =
33. 33.860 − 578 =
34. 34.726 − 637 =
35. 35.779 − 397 =
36. 36.495 − 448 =
37. 37.860 − 667 =
38. 38.526 − 127 =
39. 39.606 − 589 =
40. 40.553 − 427 =

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths