All decimal numbers can be expressed as a fraction. Decimal to fraction conversion is usually a two-step operation.
Fractions and decimals are very similar. In fact, decimal numbers are more correctly known as decimal fractions and fractions with numerators and denominators are, to give them a longer name, common fractions. Help your child to understand that (common) fractions and decimal (fractions) have the same meaning – part of the whole.
Decimals are fractions that have powers of ten as their denominators. Or, to say another way, they have 10, 100, 1000, and so on as the bottom number of the fraction.
The main thing when we convert from decimal to common fractions is to find out what we are dealing with. Is it tenths? Is it hundredths? Or is it thousandths?
The examples below show decimals can be shown as common fractions.
|We write as a decimal||We read, or say||We write as a common fraction|
|.597||.||5||9||7||five hundred ninety-seven thousandths||
|.439||.||4||3||9||four hundred thirty-nine thousandths||
The place value of the number on the right tells whether the common fraction is in tenths, hundredths, thousandths, and so on.
Consider reviewing how place value for tenths, hundredths, and thousandths are used with decimal numbers before working on converting decimal to common fractions.
Common fractions are usually written in simplest form. Sometimes this is also called writing fractions using the lowest terms. You'll find more about how to simplify fractions here.
To simplify a common fraction we find the greatest common factor for the numerator and the denominator and then use it to divide both. The steps below show an example of how to do this:
|What is the fraction?||
|Find the common factors||1 , 2 , 4|
|Find the greatest common factor||4|
|Divide 16 (the numerator) by 4||64 ÷ 4 = 16|
|Divide 20 (the denominator) by 4||100 ÷ 4 = 25|
|Write the fraction in simplest form||
If necessary, review the concept of equivalent fractions with your child before working on simplifying common fractions.
The worksheets below will help with changing between fractions and decimals.
You can try this decimals and percentages as fractions game for a little educational fun.
Practicing converting between decimals and proper fractions with the worksheets and the Equivalents Chart is a good way for your child to reinforce their understanding of the concept.