Mathematics•Addition and Subtraction
Adding Near Multiples of 10 and 100
Add and subtract numbers like 99, 199, 48, 52
10 minIncludes video
Learning Objective
4Nc8: Add and subtract near multiples of 10 or 100 to or from three-digit numbers
Strategy: Adjust and Compensate
To add 99, add 100 then subtract 1:
367 + 99 = 367 + 100 - 1 = 467 - 1 = 466
To subtract 198, subtract 200 then add 2:
543 - 198 = 543 - 200 + 2 = 343 + 2 = 345
More Examples
278 + 49 = 278 + 50 - 1 = 328 - 1 = 327
652 - 97 = 652 - 100 + 3 = 552 + 3 = 555
Video: Khan Academy (CC BY-NC-SA 4.0) | Aligned to Cambridge Primary 4Nc8