The document is a lesson on proportions that includes examples and practice problems. It defines a proportion as an equation that shows two equivalent ratios. It provides examples of using cross products to solve proportions, such as finding the missing value in 3 = n / 4 16 by setting the cross products equal: 3= n / 4 16, 4n = 3*16, 4n = 48, n = 12. Students are given additional practice problems to solve proportions using cross products.

1. Name ____________________________________ Date __________________
Mrs. Labuski / Mrs. Rooney Period __________ Lesson 8-2 Proportions
VOCABULARY DEFINITION EXAMPLE
PROPORTION
First write the ratio of triangles to circles:
Number of triangles =
Number of circles =
Next separate the triangles and the circles into two equal groups:
Now write the ratio of triangles to circles in each group:
Number of triangles in each group =
Number of circles in each group =
A proportion is shown by the models is =
You can use Cross Products to complete proportions.
Find the missing value in the proportion 3 = n
4 16
The cross products are equal. 3= n
4 16
4 n = 316
4n =
n=

3. Name ____________________________________ Date __________________
Mrs. Labuski / Mrs. Rooney Period __________ Lesson 8-2 Proportions
VOCABULARY DEFINITION EXAMPLE
An equation that shows 4=8
PROPORTION
two equivalent ratios. 2 4
First write the ratio of triangles to circles:
Number of triangles =
Number of circles =
Next separate the triangles and the circles into two equal groups:
Now write the ratio of triangles to circles in each group:
Number of triangles in each group =
Number of circles in each group =
A proportion is shown by the models is =
You can use Cross Products to complete proportions.
Find the missing value in the proportion 3 = n
4 16
The cross products are equal. 3= n
4 16
4 n = 316
4n =
n=

4. 8n = 48 4n = 180 6n = 180
÷8 ÷8 ÷4 ÷4 ÷6 ÷6
n=6 n = 45 n = 30
10n = 20 3n = 18 3n = 42
÷10 ÷10 ÷3 ÷3 ÷3 ÷3
n=2 n=6 n = 14
3n = 30 9n = 36 2n = 130
÷3 ÷3 ÷9 ÷9 ÷2 ÷2
n = 15 n=4 n = 65

5. money 1.25 = x
miles 0.5 3
0.5x = 3 x 1.25
0.5x = 3.75
÷0.5 ÷0.5
x = 7.50
Practice 20 = x
Lessons 5 20
5x = 400
÷0.5 ÷0.5
c = 80

6. p. 400#6-19 p. 401 #26