3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 82 · 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. 1.573 + 202 =
2. 2.151 + 135 =
3. 3.202 + 241 =
4. 4.705 + 612 =
5. 5.383 + 483 =
6. 6.612 − 236 =
7. 7.740 + 554 =
8. 8.466 + 531 =
9. 9.610 − 207 =
10. 10.963 − 307 =
11. 11.341 + 311 =
12. 12.603 − 209 =
13. 13.458 + 401 =
14. 14.488 − 164 =
15. 15.787 − 263 =
16. 16.199 + 533 =
17. 17.412 − 202 =
18. 18.174 + 155 =
19. 19.699 − 315 =
20. 20.624 − 129 =
21. 21.416 − 216 =
22. 22.762 + 423 =
23. 23.759 + 231 =
24. 24.229 + 192 =
25. 25.548 − 134 =
26. 26.576 − 325 =
27. 27.746 − 179 =
28. 28.907 − 541 =
29. 29.654 − 155 =
30. 30.463 − 187 =
31. 31.717 − 235 =
32. 32.877 − 517 =
33. 33.879 − 264 =
34. 34.947 − 664 =
35. 35.497 + 266 =
36. 36.887 − 408 =
37. 37.194 + 576 =
38. 38.703 + 447 =
39. 39.209 + 134 =
40. 40.637 + 411 =

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