By Anonymous on Friday, March 31, 2000 - 03:11 pm:
I am a Year Six child and I have spotted a pattern. I think that if a fraction has a numerator of 1 and a denominator that is a multiple of three that the equivalent decimal fraction will be recurring. Is this true? Have other famous mathematicians worked on this conjecture?
By Dan Goodman (Dfmg2) on Friday, March 31, 2000 - 07:39 pm:
You're right: well done.
In fact, the decimal will recur if the denominator is divisible by
any prime number other than 2 and 5.
So if 3 divides the denominator, or if 7 or 11 or 13 or 17 or 19 or
any prime number other than 2 and 5 divide the denominator, the
decimal expansion will be recurring.
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