3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 813 · 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. 1.401 + 353 =
2. 2.541 − 134 =
3. 3.536 + 125 =
4. 4.498 + 685 =
5. 5.523 − 261 =
6. 6.828 − 414 =
7. 7.582 − 465 =
8. 8.388 + 429 =
9. 9.948 − 282 =
10. 10.769 − 201 =
11. 11.525 − 295 =
12. 12.652 − 169 =
13. 13.723 + 654 =
14. 14.535 − 131 =
15. 15.327 + 643 =
16. 16.448 + 167 =
17. 17.476 − 301 =
18. 18.952 − 704 =
19. 19.472 − 129 =
20. 20.123 + 118 =
21. 21.786 + 241 =
22. 22.383 + 568 =
23. 23.302 + 521 =
24. 24.897 − 572 =
25. 25.191 + 504 =
26. 26.624 + 515 =
27. 27.799 − 464 =
28. 28.501 − 228 =
29. 29.148 + 323 =
30. 30.569 − 414 =
31. 31.522 − 185 =
32. 32.176 + 333 =
33. 33.560 − 248 =
34. 34.196 + 261 =
35. 35.555 + 392 =
36. 36.536 + 431 =
37. 37.755 + 127 =
38. 38.669 + 556 =
39. 39.541 − 276 =
40. 40.520 + 424 =

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