When it comes to changing fractions and decimals to percentages, it is very important that you know the method for each conversion. In this post, we will discuss first how to convert fractions to percentages and then decimals to percentages. So let's start!
Changing Fractions to Percentages
In order to change a fraction to a percentage, you need to use equivalent fractions. Find out what I mean by understanding the following guided problem:
Let's say that we have the fraction 5/25
In order to convert this into a percentage, we need to first review what a percentage is:
Remember: A percentage is a ratio out of a 100.
That means that we can make 5/25 equivalent to another fraction with a denominator of a 100:
We can use proportion to make it easier for us:
---- = -----
Now, use the easiest method for equivalent fractions:
Multiply both the numerator and denominator by the same number to get an equivalent fraction.
Now if we look at our proportion, we can see that we have to multiply a number by 25 to get 100. Well, what if we divide 100/25 to get the number? Let's try it and find out whether it works!
100/25 equals 4.
4 multiplied by 25 equals 100.
Yes! It works!
So that means we now have to multiply the numerator, 5 by 4 to get our equivalent fraction:
5 *4 20
---- = -----
25 *4 100
So now we know that 20/100 is equivalent to 5/25.
Now remember that a percentage is a ratio out of a 100.
So, 20 out of 100 is the same thing as 20%!
That means that 5/25 is the same thing as 20%!
Changing Decimals to Percentages
Let's say that we have the decimal number .54
When changing a decimal number to a percentage, all you have to do is look at the place value of the numbers. Remember that the decimal point is a 1. The digits after are in the tenths and hundredths. The last digit, 4, is in the hundredths place. That is the same thing as 4/100. Now look at how many hundredths you have. You have 54 hundredths. That means that .54 is the same thing as 54 hundredths or 54/100!
Now, remember that a percentage is just a ratio out of 100.
So, 54 out of hundredths is the same thing as 54 percent!
That means that .54 equals 54%.