Sender: "Debbie Norton" <>
Subject: Repeating Decimal
Date: Sun, 27 Sep 1998 15:38:47 -0500

Could you PLEASE give the formula to find out the number of digits in a repeating decimal before it repeats. I have been trying to get it for weeks from Math sites on the Internet. Can you please, please help me ?

Hi Chris,

I am not suprised that you have been unable to find an answer to your question. In the Quandaries and Queries section of Math Central is a note called Repeating Decimals which has a justification for the fact that if the fraction m/n is in lowest terms then its decimal expansion has a repeating part with at most n-1 digits. To do anything more requires a knowledge of number theory that is often taught at the third year university level. Even at this level there is no nice formula.

Chris and Penny

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