Home  Teacher  Parents  Glossary  About Us  



Our decimal system of numbers lets us write numbers as large or as small as we want, using a secret weapon called the decimal point. In our number system, digits can be placed to the left and right of a decimal point, to indicate numbers greater than one or less than one. The decimal point helps us to keep track of where the "ones" place is. It's placed just to the right of the ones place. As we move right from the decimal point, each number place is divided by 10.
We can read
the decimal number 127.578 as "one hundred twenty seven and five hundred
seventyeight thousandths". But in daily life, we'd usually read it as
"one hundred twenty seven point five seven eight."
Here is another way we could write this number:
Notice that
the part to the right of the decimal point, five hundred seventyeight thousandths,
can be written as a fraction: 578 over 1000. However, you will hardly ever
see a decimal number written like this.
Why do you think this is? You can see that our decimal code is a very handy
and quick way to write a number of any size!
Examples
Here's how to write these numbers in decimal form:
Three
hundred twentyone and seven tenths
321.7
(6
x 10) + (3 x 1) + (1 x 1/10) + (5 x 1/100)
63.15
Five
hundred fortyeight thousandths
0.548
Five
hundred and fortyeight thousandths
500.048
Hint #1: Remember to read the decimal point as "and"  notice in the last two problems what a difference that makes!
Hint #2: When writing a decimal number that is less than 1, a zero is normally used in the ones place:
0.526 not .526
Homework Help  PreAlgebra  Numbers  Email this page to a friend 