161 - 89 = 72 |
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Make 161. |
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Subtract 9 ONES. But there is only 1 ONE. So subtract 1 ONE . . . then trade 10 ONES for 1 TEN. |
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Now subtract the remaining 8 ONES. Then subtract 8 TENS by first subtracting 5 TENS . . . |
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Then trade 10 TENS for 1 HUNDRED and subtract the rest (3) of the TENS. Read the answer 72. |
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