Converting Fractions, Decimals, and Percents
From middle school and beyond, having the ability to convert between fractions, decimals, and percents is a foundational skill that students need to have so that they can build upon it. I have been teaching this concept for some time now, and I’ve learned a “few tricks” along the way to make this concept simple and understandable for students.
Converting Decimals to Percents and Converting Percents to Decimals
As with all math, there are so many ways to solve problems. One of the easiest ways that I have found to teach converting decimals to percents and converting percents to decimals is the “Dr. Pepper” method. To begin, write out DP (“Dr. Pepper”), but the D is for decimal and the P is for percent. If you are converting from a percent to a decimal, you are going from right to left, so you would start at the decimal point (very important to stress), and you would move it two places to the left. For example, if you have 25%, the decimal would be located after the five, and if you move it two places to the left, it becomes the decimal 0.25. When converting from a decimal to a percent, you do the opposite and move the decimal two places to the right. For example, 0.25 will become 25%. An example is shown in the picture below.
I also think that is is important that students understand how this works. If they want to convert a decimal to a percent, they can multiply by 100, and if they want to convert a percent to a decimal, they can divide by 100. I have just found that the “Dr. Pepper” method is easy to remember!
Converting Decimals to Fractions and Converting Fractions to Decimals
When converting from a decimal to a fraction, the best way to remember is to write what you read! For example, if you have the decimal 0.2, you would read this as two-tenths. To write it as a fraction, you would just write two-tenths in fraction form, and then simplify! Check out the other examples in the photo below! If your students need more practice with reading and verbalizing decimals, you can check this free I Have, Who Has game.
Sometimes, changing decimals to fractions can be a little bit complicated. What if you have a repeating decimal? Well, the easiest way to convert this is to place the repeating numbers over the same number of 9s. For example, if you have 0.1111111…, you would place a one over 9 because there is only one number that is repeating. If you have 0.363636…, you would place 36 over 99 because the 36 is repeating. There are more examples in the picture below.
When converting from a fraction to a decimal, this is fairly simple. You just divide! The fraction bar is like a division symbol. Students can use a calculator or they can practice their long division.
Converting Percents to Fractions and Converting Fractions to Percents
To convert a percent to a fraction and vice versa, you will have to go through two steps. You will have to convert to a decimal first before you convert to the other. For example, when converting from a percent to a fraction, you must first change that percent to a decimal, and then convert to a fraction. So, if you have 25%, you will move two places to the left to change this to a decimal, 0.25, and then you can “write what you read”, 25/100, which simplifies to ¼.
To convert a fraction to a percent, you must also convert the fraction to a decimal before you convert to a percent. For example, if you have ¼, when you divide you get 0.25. Then you can move the decimal two places to the right, and this will give you 25%.
These are not the only ways to convert! These are just the methods that I have found to be the simplest. I will also suggest that if you have a fraction that you can easily make an equivalent with a denominator of 100, you can easily change this to a percent. So, let’s say you have the fraction 37/100. This is 37%. If you have the fraction ¼, this can easily be converted to 25/100, which is 25%.
Converting Fractions, Decimals, and Percent Games
There are probably so many games that are available for converting fractions, decimals, and percents. Here is an I Have, Who Has Game – Converting Fractions, Decimals, and Percents that I have played in my classroom and that I love! To make sure the game runs smoothly, I suggest having students convert their “I Haves” to a fraction, decimal, and a percent before the game begins so that it runs smoother. I actually play a few times in a row and switch the cards up to get extra practice in!
If you interested in a video to help you brush up on your skills, I created a converting fractions, decimals, and percents lesson video for my students. It was created for a flipped classroom, and it’s a bit aged, but you may find it helpful, so I thought I’d share!
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