Who is asking: Student
Level: All
Question:
I have another question please, WHY do we invert and multiply when dividing fractions? I know that's what we do but WHY? What is the reasoning behind it?
Hi again Debbie,
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I find it helps to reword a division problem as a multiplication problem. Reword | ||
| "What is 15 divided by 5?" | ||
| to | ||
| "What number, multiplied by 5, gives 15?" | ||
| That is | ||
| 15/5 = ? | ||
| becomes | ||
| ? x 5 = 15 | ||
| Clearly the answer here is 3 since 3 x 5 = 15. | ||
| Similarly with fractions | ||
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| Here the answer is | ||
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| since | ||
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| The rule "invert and multiply" is just a handy way to say | ||
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Penny