3-Digit Mental Addition and Subtraction Worksheet

Mental maths lesson 20: Add and subtract 3-digit numbers left to right · Set 185 · 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. 1.959 − 326 =
2. 2.475 − 323 =
3. 3.616 + 489 =
4. 4.989 − 502 =
5. 5.755 + 461 =
6. 6.455 − 178 =
7. 7.632 + 442 =
8. 8.920 − 315 =
9. 9.345 + 414 =
10. 10.969 − 741 =
11. 11.336 + 219 =
12. 12.727 + 115 =
13. 13.137 + 411 =
14. 14.581 + 279 =
15. 15.476 − 181 =
16. 16.366 + 268 =
17. 17.463 + 613 =
18. 18.944 − 761 =
19. 19.288 + 532 =
20. 20.520 − 172 =
21. 21.517 − 299 =
22. 22.544 − 131 =
23. 23.305 + 472 =
24. 24.603 − 496 =
25. 25.681 − 511 =
26. 26.925 − 253 =
27. 27.531 − 429 =
28. 28.777 + 677 =
29. 29.950 − 745 =
30. 30.782 − 385 =
31. 31.719 − 187 =
32. 32.958 − 776 =
33. 33.571 + 514 =
34. 34.630 − 171 =
35. 35.896 − 466 =
36. 36.925 − 513 =
37. 37.588 − 216 =
38. 38.958 − 209 =
39. 39.743 + 121 =
40. 40.767 − 536 =

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