Decimals, Fractions, Percents….Oh My! Relax, it isn’t that scary. Click and you’ll learn for yourself.
It is time to eliminate all distractions, put on your detective hat, and pay close attention.
Decimal to Percent
In order to convert a decimal to a percent, multiply the decimal by 100. Next, place a percent sign at the end of the product. Now, study the following examples. It’s okay to use the calculator.
.70 x 100 = 70; thus 70%
.90 x 100 = 90; thus 90%
.58 x 100 = 58; thus 58%
.8 x 100 = .80; thus 80%
.123 x 100 = 12.3; thus 12.3%
1.10 x 100 = 110; thus 110%
Did you notice that each time you multiplied by 100, the decimal point was moved two places to the right? If not, look again! This observation will save you time. Also, notice the “.8” example. If you bypass multiplication process and just move the decimal to the right, it may be necessary to add a zero. In summary, move the decimal two places to the right whenever asked to convert from decimals to percents from this day forth.
Percent to Decimal
Now, let us reverse the process. If it is required to multiply to convert from decimal to percent, do the opposite to convert from percents to decimals. Therefore, drop the percent sign, and divide by 100. . Study the following examples.
70% = 70 / 100 = .70
90% = 90 / 100 = .90
58% = 58 / 100 = .58
80% = 80 / 100 = .8
12.3% = 12.3 / 100 = .123
110% = 110 / 100 = 1.10
5% = 5 / 100 = .05
Did you notice that each time you divided by 100, the decimal point was moved two places to the left? If not, look again! This observation will save you time too. Take another look at the last example, “5%.” If you divide by 100 using a calculator, .05 is the answer. However, if you take the short cut and move the decimal two places to the left, it is necessary to add a zero in front to get the correct result.
The purpose of this tip is to help you remember which way to move the decimal.
When converting from decimals to percents…
Think: Where am I supposed to place the percent sign? …behind the number
And which direction do I have to go in order to put the percent sign behind the number? …to the right
When converting from percents to decimals…
Think: What am I supposed to do with the percent sign? Drop it. Next, where am I supposed to place the decimal? …in front of the number
And which direction do I have to go in order to place the decimal in front of the number? …to the left
Convert Percents to Fractions
Did you know percents were fractions?! Yes, I’m not kidding. Remember fractions represent part of a whole. (part/whole) Let me ask you a question. What percentage of the problems do you hope to get correct on a test? Of course, you want to get the whole test correct or 100% correct. Anything less than a hundred would representpart of a hundred percent. Thus, a grade of 88% would be the same as 88 out of 100 correct or 88 /100. In other words, you were only able to get part of the 100 correct.
Let’s assume a friend decided to watch television all weekend instead of studying, and she made a 46 on her quiz. Thus, she answered 46% correct, or she earned 46 out of a possible 100 points. The fraction, 46/100, represents the same results.
Again, all percents are fractions. However, there is something unique about the denominators of percents. Have you noticed? One hundred is the denominators for all percents.
So, write the percent without the “%” as the numerator, and write “100” as the denominator to convert percents to fractions. If necessary, simplify the fraction.
46% = 46/100 = 23/50
75% = 75/100 = ¾
25 % = 25/100 = ¼
235% = 235/100 = 2 35/100 = 2 7/20
Convert Fractions to Percents
The easiest way to convert fractions to percents is to:
1. Convert the fraction to a decimal. (Refer to the article, “Converting Fractions-Decimals” for a detailed explanation.)
2. Then, convert the decimal to a percent.
Example: ¾ = .75 = 75%
I’ve included two options for practice below. I hope you like them.