3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 391 · 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. 1.760 − 139 =
2. 2.646 − 271 =
3. 3.487 + 613 =
4. 4.678 − 241 =
5. 5.461 + 674 =
6. 6.270 + 407 =
7. 7.779 + 112 =
8. 8.874 − 335 =
9. 9.225 + 491 =
10. 10.573 + 291 =
11. 11.528 + 229 =
12. 12.168 + 395 =
13. 13.652 − 429 =
14. 14.265 + 488 =
15. 15.613 + 201 =
16. 16.165 + 404 =
17. 17.985 − 534 =
18. 18.424 − 305 =
19. 19.713 − 444 =
20. 20.145 + 525 =
21. 21.784 + 323 =
22. 22.616 + 222 =
23. 23.688 + 429 =
24. 24.558 − 165 =
25. 25.167 + 168 =
26. 26.910 − 438 =
27. 27.592 − 304 =
28. 28.582 + 436 =
29. 29.780 + 141 =
30. 30.301 + 555 =
31. 31.417 − 275 =
32. 32.821 − 403 =
33. 33.537 + 166 =
34. 34.800 − 505 =
35. 35.701 − 419 =
36. 36.861 − 252 =
37. 37.154 + 141 =
38. 38.484 − 137 =
39. 39.341 + 255 =
40. 40.128 + 523 =

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