Changing a Fraction to a Percent

Lesson Plan - Get It!

Audio:

Fractions, decimals, and percentages are used to express parts of a whole.

They express the same amount but are written differently. On a piece of paper, write down how you use or where you have seen fractions, decimals, and percentages. Discuss your thoughts with a parent or teacher.

• Fractions are commonly used in cooking and measuring.
• Decimals are commonly used in money.
• Percentages are commonly used in sports and to display discounts and sales at stores.

Every fraction can be written as a decimal or percent.

To change a fraction into a percent, you need to complete two steps:

1. The first step is to convert the fraction to a decimal.
2. Then, convert the decimal to a percent. You can use a calculator or long division to convert a fraction to a percent. If the denominator of the fraction is a 10 or 100, it will make the conversion faster!

Now you will watch a video to review how fractions and percentages are related. As you watch Math Antics - Percents and Equivalent Fractions, look for the answers to these questions:

• When a percentage is written as a fraction, what value should the denominator, or bottom number, be equal to?
• What is a fraction that is equivalent to ½?
• How would you write 75% as a fraction?

After the video, discuss with a parent or teacher how to change a fraction to a percent if the denominator is 100.

Example

Convert ³⁄₁₀ to a percent.

1. First, convert ³⁄₁₀ to a decimal: ³⁄₁₀ is 0.3 or 0.30 as a decimal.
2. Now, multiply the decimal by 100, or move the decimal point two places to the right. The fraction ³⁄₁₀ is written as 30%.

Another way to solve this problem is to change the fraction to ?⁄100. Since percent means “per 100,” if a fraction has a denominator of 100, the top number is written with a percentage symbol.

1. The denominator in ³⁄₁₀ is ten, and that can easily be changed to have a denominator of 100 by multiplying by 10.
2. Multiply the numerator and the denominator by 10 to create an equivalent fraction. ³⁄₁₀ becomes ³⁰⁄₁₀₀, which is 30%. This method will only work with a fraction that has a denominator that can be multiplied by another whole number to become 100.

Example

What is ⁵⁄₈ as a percent?

The simplest method is to use a calculator when converting a fraction to a percent.

1. Divide the top of the fraction by the bottom. In this example, type in “5 ÷ 8 = .” The calculator should show 0.625.
2. Next, multiply that answer by 100 and your answer is 62.5%. Don’t forget to add the % symbol to your answer.

Discuss the question you read at the start of this lesson with a parent or adult: Who gets to eat more of the pizza, Mike or Sarah? Think carefully!

Mike and Sarah are sharing a pizza. Mike says he gets to eat ½ of the pizza. Sarah says she gets to eat 50% of the pizza. Who gets to eat more of the pizza?

Now, you will move to the Got It? section to convert fractions to percentages as you play games and complete interactive practice.