1. Ratios and Proportions
Lesson 6.1

2. Getting Started… Name an equivalent fraction :
Which fraction is larger?

3. Definitions Ratio: a comparison of two quantities by division.
Equal Ratio: Represent the same comparison
Proportion: An equation that states two ratios are equal is called a proportion.
Cross Product Property:

4. How to Recognize a Ratio
How can we express the ratio of blue to yellow squares?
As a fraction 8/12  2/3
With a colon: 2 : 3
With the word, “to” : to 3

5. THIS IS ALSO A PROPORTION!
Equal Ratios
Getting Started question…
THIS IS ALSO A PROPORTION!

6. Proportions Proportions are also expressed in three ways.
A proportion is just 2 ratios combined.
5 is to 6 as 10 is to 12
5 : 6 :: 10 : 12

7. Cross Products Since 21 is Greater than 16 16, 3/8 is larger!
Which fraction is larger?
Instead of finding the LCD, we could use the cross product property.
Since 21 is
Greater than
16, 3/8 is
larger! 16 21

8. Try a few!
Use the cross-products property to determine if the proportion is true or false.
216
210
FALSE!
42x
42x
TRUE!

9. Homework
Extra Practice 6.1