3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 519 · 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. 1.903 − 781 =
2. 2.760 + 605 =
3. 3.756 − 486 =
4. 4.511 + 211 =
5. 5.287 + 174 =
6. 6.693 + 269 =
7. 7.603 − 398 =
8. 8.491 + 128 =
9. 9.546 − 135 =
10. 10.747 − 305 =
11. 11.713 − 149 =
12. 12.697 + 666 =
13. 13.422 − 125 =
14. 14.581 + 175 =
15. 15.567 − 285 =
16. 16.986 − 136 =
17. 17.989 − 576 =
18. 18.269 + 246 =
19. 19.561 + 139 =
20. 20.538 + 272 =
21. 21.419 − 233 =
22. 22.279 + 565 =
23. 23.673 − 555 =
24. 24.839 − 253 =
25. 25.917 − 252 =
26. 26.624 − 314 =
27. 27.205 + 575 =
28. 28.982 − 747 =
29. 29.667 − 509 =
30. 30.565 − 139 =
31. 31.674 + 511 =
32. 32.264 + 444 =
33. 33.542 + 355 =
34. 34.340 + 289 =
35. 35.430 − 266 =
36. 36.574 − 282 =
37. 37.961 − 632 =
38. 38.719 − 186 =
39. 39.632 + 223 =
40. 40.988 − 638 =

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