Written Form of Decimals

Date: 03/21/2001 at 09:19:47
From: ceci stotz
Subject: Written form for decimals

Hello...

What is the CORRECT way to write decimals?

Example: 343.25 

Is it: three hundred forty-three and twenty-five hundredths - OR- 
Is it: three hundred forty-three and twenty-five one hundredths? 

The "one" is the question. Do you add "one" in front of "hundredths"? 
What about hyphens, where do they go?

Example: 46.6 

Is it: forty-six and six tenths -OR- is it forty-six and six one 
tenths?

Also for thousandths place?

Thank you.

Date: 03/21/2001 at 12:00:44
From: Doctor Rob
Subject: Re: Written form for decimals

Thanks for writing to Ask Dr. Math, Ceci.

For 343.25, it is "three hundred forty-three and twenty-five 
hundredths."

For 46.6, it is "forty-six and six tenths."

For 82.554, it is "eighty-two and five hundred fifty-four 
thousandths."

For 0.1008, it is "one thousand eight ten-thousandths."

The word "and" is used only to designate the location of the decimal
point. There are single words for numbers from 1 to 20, 30, 40, 50,
60, 70, 80, and 90.  All other numbers from 21 to 99 use a hyphen.
You also must use a hyphen when talking about ten-thousandths,
hundred-billionths, and similar fractional denominations.  Since
hundredths and one-hundredths are the same, the shorter form is used.

I have always thought it sounds redundant to say "one one-hundredth of 
an inch,"  but some people do use this terminology.

- Doctor Rob, The Math Forum
  http://mathforum.org/dr.math/