The number '''142857''' has the curious property that, if it is multiplied by any number from 1 to 6, the result is a number with the same digits in the same order (a [[cyclic permutation]]).
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For example:
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:142857 × 1 = 142857
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:142857 × 2 = 285714
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:142857 × 3 = 428571
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:142857 × 4 = 571428
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:142857 × 5 = 714285
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:142857 × 6 = 857142
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This property is closely related to the facts that
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:1/7 = 142857/999999
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and that 1/7 expressed as a [[decimal]] is
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:0.142857142857142857142857142857...
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Investigating the number 142857 can lead a student into an understanding of repeating decimals and [[rational numbers]].
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== Similar Numbers ==
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142857 is the only multi-digit decimal number with this property. However, if leading zeros are allowed on a number, some other examples are: