Using Proportions and other strategies to solve for rates. 7.RP.2c

1. 6-1 & 6-6
Solving for Equivalent
Ratios
7.RP.2c Represent proportional
relationships by equations.

2. How many Purple
1. Describe the
do I need to add
ratio of
to this to keep
Green:Purple
the ratio the
same?

3. Partner-Group-Class
How did you solve it?
Can you make it into an equation?
Explain your process.

4. Notes:
4 Methods:
1. Simplify
2. Combination of mult. and div.
3. Cross Products into equation form
4. Find Unit Rate

5. 1. Simplify
15p = xp
3g 8g
5p = xp Now talk about the answer
1g 8g
or 3g = 8g
15p xp

6. Practice: Simplify
6 dollars = 24 dollars
k kids 28 kids
x adults for 16 kids, and 3 adults for 12 kids
c cars = 18 cars
7 people 42 People
2.5 parts = 7.5 parts
4.5 pieces x pieces

7. 2. Combinations (x ÷)
12p = xp
8g 10g
Use x and ÷ to go from 8 to 10
Do the same with 15.
÷4x5
x5÷4

8. Practice combinations
20 kids = 16 kids
6 families x families
5 pounds of dry ice melts in 30 hours,
and x pounds melts in 24 hours
3 kids = 12 kids
8 families x families
16 winners = 28 winners
200 entries x entries

9. 3. Cross Products
3x
15p = Xp
3g 8g
15(8)
3x=15(8)
3x=120

10. Practice Cross Products
1.6 = 2
m 3
4 notebooks = 6 notebooks
2.8 pounds w pounds
5 meters in 7 minutes and
x meters in 35 minutes
3.8 mm = x mm
5.2 meters 10.4 meters

11. 4. Unit rates
15p = Xp 15p = Xp
÷ 3g 8g
3g 8g
15÷3 = x÷8 x
5 = x÷8 (5purple for every green is the unit rate)
5(8) = x
Works well when missing number is on top-right.

12. Practice: Find Unit Rate
9 miles = b miles
3 signs 40 signs
6 teaspoons = x teaspoons
2 Tablespoons 1.5 Tablespoons
14pieces = x pieces
4 strings 45 strings