3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 954 · 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. 1.612 − 193 =
2. 2.200 + 342 =
3. 3.472 + 122 =
4. 4.894 − 632 =
5. 5.239 + 254 =
6. 6.359 + 579 =
7. 7.466 + 581 =
8. 8.676 + 455 =
9. 9.308 + 494 =
10. 10.785 + 281 =
11. 11.513 + 333 =
12. 12.168 + 308 =
13. 13.572 + 249 =
14. 14.658 + 536 =
15. 15.897 − 624 =
16. 16.279 + 418 =
17. 17.124 + 654 =
18. 18.622 + 636 =
19. 19.620 − 193 =
20. 20.643 + 323 =
21. 21.945 − 117 =
22. 22.536 + 461 =
23. 23.807 − 575 =
24. 24.662 − 537 =
25. 25.280 + 603 =
26. 26.256 + 122 =
27. 27.174 + 199 =
28. 28.962 − 854 =
29. 29.519 + 408 =
30. 30.534 − 284 =
31. 31.661 + 276 =
32. 32.377 + 457 =
33. 33.899 − 222 =
34. 34.291 + 359 =
35. 35.333 + 181 =
36. 36.431 − 234 =
37. 37.476 − 186 =
38. 38.909 − 668 =
39. 39.592 + 491 =
40. 40.479 − 253 =

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