COMPENSATION STRATEGY

Add too much on purpose, then subtract the extra. A slick mental shortcut.

L3L4

CS.N.3.2·Using calculation techniques with numbers 0–10000(III)

Section 1 / 3

THE OVER-ADD TRICK

Compensation means deliberately adding more than you need, then fixing it. To add 99, just add 100 and subtract 1. It sounds sneaky, but it is mathematically perfect!

99 + 47

1100 + 47 = 147

2Subtract 1 (you added extra): 147 − 1 = 146

= 146

LEADER TIP

Show both ways: add too much then subtract, or redistribute from one number to the other. Let students pick their favourite.

BEFORE THIS LESSON, TRY

Friendly Numbers

PRACTICE WITH THESE GAMES

Quick Calculate

Math Sprint

Addition Quiz

Want more practice? Generate printable worksheets with similar problems.

Go to Worksheets

CONTINUE WITH:

Mental Addition

COMPENSATION STRATEGY

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COMPENSATION STRATEGY