Lesson 10: What Are Percentages?

10.1: Dollars and Cents

1. A sticker costs 25 cents. How many dollars is that?
2. A pen costs 1.50 dollars. How many cents is that?
3. How many cents are in one dollar?
4. How many dollars are in one cent?

10.2: Coins

1. Complete the table to show the values of these U.S. coins.

   coin row 1 value (cents) penny nickel dime quarter half dollar dollar

The value of a quarter is 25% of the value of a dollar because there are 25 cents for every 100 cents.

2. Write the name of the coin that matches each expression.

1. 25% of a dollar
2. 5% of a dollar
1. 1% of a dollar
2. 100% of a dollar
1. 10% of a dollar
2. 50% of a dollar
1. The value of 6 dimes is what percent of the value of a dollar?
1. The value of 6 quarters is what percent of the value of a dollar?

A \$1 coin is worth 100% of the value of a dollar. Here is a double number line that shows this. 1. The coins in Jada’s pocket are worth 75% of a dollar. How much are they worth (in dollars)? 2. The coins in Diego’s pocket are worth 150% of a dollar. How much are they worth (in dollars)? 1. Elena has 3 quarters and 5 dimes. What percentage of a dollar does she have? Summary A percentage is a rate per 100. We can find percentages of \$10 using a double number line where 10 and 100% are aligned, as shown here:

Looking at the double number line, we can see that \$5.00 is 50% of \$10.00 and that \$12.50 is 125% of \$10.00.

Glossary

percent

percent

The word percent means “per 100” or “for each 100” and is usually written symbolically like this: %.

percentage

percentage

A percentage is a quantity described by a rate per 100.