Lesson 10: What Are Percentages?
Let’s learn about percentages.
Illustrative Math Unit 6.3, Lesson 10 (printable worksheets)
Lesson 10 Summary
The following diagram shows how to find percentages using a double number line.
Lesson 10.1 Dollars and Cents
Find each answer mentally.
- A sticker costs 25 cents. How many dollars is that?
- A pen costs 1.50 dollars. How many cents is that?
- How many cents are in one dollar?
- How many dollars are in one cent?
Scroll down the page for the solution to the “Are you ready for more?” section.
Lesson 10.2 Coins
- Complete the table to show the values of these U.S. coins.
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.
a. 25% of a dollar
b. 5% of a dollar
c. 1% of a dollar
d. 100% of a dollar
e. 10% of a dollar
f. 50% of a dollar
3. The value of 6 dimes is what percent of the value of a dollar?
4. The value of 6 quarters is what percent of the value of a dollar?
Are you ready for more?
Find two different sets of coins that each make 120% of a dollar, where no type of coin is in both sets.
120% of a dollar = $1.20
Set 1 = 12 dimes or 1 dollar and 2 dimes
Set 2 = 4 quarters and 4 nickels
Lesson 10.3 - Coins on a Number Line.
A $1 coin is worth 100% of the value of a dollar. Here is a double number line that shows this.
- The coins in Jada’s pocket are worth 75% of a dollar. How much are they worth (in dollars)?
- The coins in Diego’s pocket are worth 150% of a dollar. How much are they worth (in dollars)?
- Elena has 3 quarters and 5 dimes. What percentage of a dollar does she have?
The word percent means “for each 100.” The symbol for percent is %.
For example, a quarter is worth 25 cents, and a dollar is worth 100 cents. We can say that a quarter is worth 25% of a dollar.
For example, a fish tank can hold 36 liters. Right now there is 27 liters of water in the tank. The percentage of the tank that is full is 75%.
Lesson 10 Practice Problems
- What percentage of a dollar is the value of each coin combination?
a. 4 dimes
b. 1 nickel and 3 pennies
c. 5 quarters and 1 dime
- a. List three different combinations of coins, each with a value of 30% of a dollar.
b. List two different combinations of coins, each with a value of 140% of a dollar.
- The United States government used to make coins of many different values. For each coin, state its worth as a percentage of $1.
a. ½ cent
b. 3 cents
c. 20 cents
- Complete the double number to line show percentages of $50.
- Elena bought 8 tokens for $4.40. At this rate:
a. How many tokens could she buy with $6.05?
b. How much do 19 tokens cost?
- A snail travels 10 cm in 4 minutes. At this rate:
a. How long will it take the snail to travel 24 cm?
b. How far does the snail travel in 6 minutes?
- a. 3 tacos cost $18. Complete the table to show the cost of 4, 5, and 6 tacos at the same rate.
b. If you buy t tacos for c dollars, what is the unit rate?
|number of tacos
||cost in dollars
||rate in dollars per taco
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