Why does 10 × 9 = 90?

Because adding 10 9's together makes 90.

That is, because 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 = 90.

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Keep practicing
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144

Why does 10 × 9 = 90?

Because adding 10 9's together makes 90.

That is, because 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 = 90.

Keep practicing