ADDING & SUBTRACTING NEAR-MULTIPLES

Add or subtract near-multiples like 99, 198, or 999 using easy adjustments.

L4L5

CS.N.3.2·Using calculation techniques with numbers 0–10000(III)CS.N.4.4·Using multiplication properties to simplify calculations(IV)

Section 1 / 3

ROUND, THEN ADJUST

Numbers like 99, 198 and 999 sit just below a friendly round number. Use the round number first, then correct by the small difference. Awkward arithmetic becomes two simple steps.

56 + 99

199 is almost 100

256 + 100 = 156

3Subtract 1: 156 − 1 = 155

= 155

45 + 198

1198 is almost 200

245 + 200 = 245

3Subtract 2: 245 − 2 = 243

= 243

LEADER TIP

Use 'adjust and compensate' language consistently: +99 = +100 then -1. Make it a class mantra.

BEFORE THIS LESSON, TRY

Rounding to Nearest 10 & 100

PRACTICE WITH THESE GAMES

Quick Calculate

Math Sprint

Addition Quiz

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ADDING & SUBTRACTING NEAR-MULTIPLES

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ADDING & SUBTRACTING NEAR-MULTIPLES