3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 215 · 40 questions

How to do it in your head (Hundreds first): Keep the first number as it is and split the second into hundreds, tens and ones. Add (or take away) the hundreds first, then the tens. Finish with the ones — bridge through a ten if you need to.

1. 1.667 − 233 =
2. 2.721 − 538 =
3. 3.749 − 163 =
4. 4.632 − 125 =
5. 5.626 − 309 =
6. 6.226 + 433 =
7. 7.268 + 661 =
8. 8.302 + 126 =
9. 9.618 + 201 =
10. 10.316 + 176 =
11. 11.462 − 316 =
12. 12.954 − 835 =
13. 13.951 − 253 =
14. 14.824 − 541 =
15. 15.347 + 469 =
16. 16.940 − 422 =
17. 17.590 − 421 =
18. 18.494 − 151 =
19. 19.256 + 276 =
20. 20.717 + 524 =
21. 21.605 + 273 =
22. 22.510 + 461 =
23. 23.812 − 195 =
24. 24.770 − 535 =
25. 25.625 + 213 =
26. 26.262 + 435 =
27. 27.480 − 281 =
28. 28.480 − 123 =
29. 29.324 + 301 =
30. 30.747 + 231 =
31. 31.532 + 167 =
32. 32.987 − 736 =
33. 33.231 + 503 =
34. 34.340 + 608 =
35. 35.737 + 676 =
36. 36.648 − 232 =
37. 37.699 + 321 =
38. 38.767 − 134 =
39. 39.570 + 676 =
40. 40.626 + 478 =

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