3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 543 · 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. 1.494 + 151 =
2. 2.626 + 361 =
3. 3.557 + 258 =
4. 4.837 − 113 =
5. 5.484 − 117 =
6. 6.414 + 518 =
7. 7.643 − 358 =
8. 8.285 + 267 =
9. 9.534 + 338 =
10. 10.428 − 215 =
11. 11.936 − 564 =
12. 12.443 − 238 =
13. 13.281 + 672 =
14. 14.760 + 121 =
15. 15.508 + 225 =
16. 16.475 + 503 =
17. 17.659 − 117 =
18. 18.554 + 512 =
19. 19.365 + 316 =
20. 20.477 + 622 =
21. 21.789 + 439 =
22. 22.797 − 534 =
23. 23.509 − 233 =
24. 24.190 + 166 =
25. 25.290 + 182 =
26. 26.208 + 667 =
27. 27.925 − 196 =
28. 28.443 − 323 =
29. 29.488 − 388 =
30. 30.461 − 151 =
31. 31.497 + 333 =
32. 32.450 − 188 =
33. 33.861 − 311 =
34. 34.788 − 127 =
35. 35.204 + 474 =
36. 36.926 − 461 =
37. 37.497 − 387 =
38. 38.676 − 545 =
39. 39.654 − 181 =
40. 40.356 + 529 =

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