3-Digit Mental Addition and Subtraction Worksheet
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.
NameDateTime takenScore ___ / 40
- 1.627 + 211 =
- 2.619 + 528 =
- 3.941 − 357 =
- 4.886 − 258 =
- 5.394 + 194 =
- 6.884 − 531 =
- 7.930 − 166 =
- 8.976 − 236 =
- 9.744 − 204 =
- 10.669 − 194 =
- 11.279 + 539 =
- 12.803 − 222 =
- 13.506 + 581 =
- 14.558 − 399 =
- 15.522 − 149 =
- 16.503 − 225 =
- 17.692 + 237 =
- 18.193 + 263 =
- 19.624 − 212 =
- 20.287 + 677 =
- 21.929 − 325 =
- 22.711 − 497 =
- 23.777 − 555 =
- 24.586 + 276 =
- 25.424 + 575 =
- 26.439 + 389 =
- 27.157 + 648 =
- 28.600 + 531 =
- 29.528 + 141 =
- 30.166 + 443 =
- 31.552 + 187 =
- 32.975 − 267 =
- 33.649 − 385 =
- 34.422 + 341 =
- 35.445 − 275 =
- 36.312 + 545 =
- 37.883 − 154 =
- 38.165 + 611 =
- 39.738 + 469 =
- 40.970 − 846 =
Answer key
- 838
- 1147
- 584
- 628
- 588
- 353
- 764
- 740
- 540
- 475
- 818
- 581
- 1087
- 159
- 373
- 278
- 929
- 456
- 412
- 964
- 604
- 214
- 222
- 862
- 999
- 828
- 805
- 1131
- 669
- 609
- 739
- 708
- 264
- 763
- 170
- 857
- 729
- 776
- 1207
- 124
Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths