The Math Forum

Ask Dr. Math - Questions and Answers from our Archives
Associated Topics || Dr. Math Home || Search Dr. Math

Recurring Decimal Notation

Date: 05/12/2003 at 13:10:30
From: Thomas.Kenning
Subject: Infinite geometric series

Nb. the dots represent that the number with a dot on the top means it 
has repetition

4.32 = 4.323232323232

0.3 = 0.333333333

The question is:
  . .
0.321 = ?

For the last question there was no dot on top of the 2, only on top of 
the 3 and the 1.

Date: 05/12/2003 at 15:02:38
From: Doctor Peterson
Subject: Re: Infinite geometric series

Hi, Thomas.

In America, the usual notation for a repeating decimal is to put a bar 
(vinculum) over the entire repeating portion:
  0.1234 = 0.1234234234...

In some parts of the world (the British part?), a dot is placed over 
the FIRST and LAST digits in the repetend:
     . .
  0.1234 = 0.1234234234...

It is not just the 2 and the 4 that repeat, but the entire string 
"234" between them.

If you have any further questions, feel free to write back.

- Doctor Peterson, The Math Forum 
Associated Topics:
Elementary Fractions
Middle School Fractions

Search the Dr. Math Library:

Find items containing (put spaces between keywords):
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

Math Forum Home || Math Library || Quick Reference || Math Forum Search

Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.