Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 247 · 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. 1.528 − 148 =
2. 2.674 − 168 =
3. 3.975 − 699 =
4. 4.829 − 687 =
5. 5.967 − 649 =
6. 6.517 − 298 =
7. 7.532 − 299 =
8. 8.858 − 699 =
9. 9.402 − 299 =
10. 10.276 − 197 =
11. 11.336 − 209 =
12. 12.890 − 438 =
13. 13.829 − 799 =
14. 14.726 − 537 =
15. 15.511 − 349 =
16. 16.358 − 298 =
17. 17.873 − 399 =
18. 18.740 − 459 =
19. 19.542 − 399 =
20. 20.706 − 557 =
21. 21.881 − 417 =
22. 22.818 − 297 =
23. 23.736 − 299 =
24. 24.933 − 697 =
25. 25.513 − 398 =
26. 26.728 − 698 =
27. 27.613 − 418 =
28. 28.867 − 298 =
29. 29.599 − 297 =
30. 30.619 − 259 =
31. 31.880 − 367 =
32. 32.417 − 208 =
33. 33.868 − 798 =
34. 34.967 − 798 =
35. 35.944 − 159 =
36. 36.681 − 597 =
37. 37.518 − 499 =
38. 38.744 − 377 =
39. 39.696 − 499 =
40. 40.996 − 399 =

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