An Arithmetical Curiosity
Write the nine digits in their order, and multiply them by 9; the result will be composed of units, excepting the next to the last, thus:
| 123456789 | ||
| 9 | ||
| ---------------- | ||
| 1111111101 |
Multiply by 18, instead of 9, and the product will consist of 2’s. By 27, and it will be 3’s. In this manner all the digits may be obtained by multiplying by the multiples of 9; as 36, 45, 54, etc.
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