RATIOS
PROPORTIONS
UNIT PRICE
HALVING INGREDIENTS
DOUBLING INGREDIENTS
100
What is the ratio of blue frogs to total frogs?
BLUE : TOTAL
3 : 8
100
Do the ratios form a proportion?
CROSS MULTIPLY!
2 x 8 = 16
3 x 5 = 15
NO! These ratios do NOT form a proportion because their cross products are not equal!
100
Find the unit price:
$5.80 for 10 ounces
unit price = cost / amount
unit price = $5.80 / 10 ounces
Unit Price = $0.58 per ounce
OR
58 cents per ounce
100
Halve 2 cups of flour
1 cup of flour
100
Double 1 cup of sugar
2 cups of sugar
200
Your math teacher gave you a unit test with 25 questions. Thirteen (13) of those questions were multiple choice and the rest were free response questions. What is the ratio of free response questions to multiple choice questions?
Free response questions: 25 - 13 = 12
Free Response : Multiple Choice
12 : 13
200
Do the ratios form a proportion?
CROSS MULTIPLY!
2 x 16 = 32
8 x 4 = 32
YES! These ratios DO form a proportion because their cross products are equal!
200
Find the UNIT RATE:
She bakes 72 cupcakes in 3 days. How many cupcakes can she bake in 1 day?
72 cupcakes / 3 days =
24 cupcakes / 1 day
200
Halve 1 cup of milk
1/2 cup of milk
200
Double 2 Tbsp of olive oil
4 Tbsp
300
Margo can read 2 books in 1 day. How many days does it take her to read 10 books?
You can set up a proportion and solve:
1/x = 2/10 OR 1/2 = x/10
***OR***
You can multiply or divide! To go from 2 to 10 in the 2nd column, you MULTIPLY BY 5. So, multiply the 1 in the 1st column by 5! 1 x 5 = 5!
It takes Margo 5 days to read 10 books!
300
Solve the proportion for x!
CROSS MULTIPLY, THEN DIVIDE!
2 x 10 = 2020 / 4 = 5
x = 5
300
Find the unit price:
unit price = cost / amount
unit price = $6.49 / 16 ounces
Unit Price = $0.41 per ounce
OR
41 cents per ounce
300
Halve 1/2 tsp of cumin
1/4 tsp of cumin
300
Double 1/2 tsp of salt
1 tsp of salt
400
Your little cousin has a toy car and truck collection. He has 3 cars for every 9 trucks. Find the missing values!
Multiply and Divide to find the missing values!
1 - 3
3 - 9
12 - 36
400
Solve the proportion for x!
CROSS MULTIPLY, THEN DIVIDE!
6 x 4 = 24
24 / 8 = 3
x = 3
400
Find the unit price:
unit price = cost / amount
unit price = $2.50 / 48 ounces
Unit Price = $0.05 per ounce
OR
5 cents per ounce
400
Halve 1/3 tsp of chili powder
1/6 tsp of chili powder
400
Double 1/4 tsp of pepper
1/2 tsp of pepper
500
There are 4 girls for every 6 boys in the school Art Club. Find the missing values!
Multiply / Divide to find the missing values!
4 - 6
12 - 18
16 - 24
500
PROPORTION:
seconds / dribbles = seconds / dribbles
3 / 13 = 27 / x
CROSS MULTIPLY, THEN DIVIDE!
13 x 27 = 351
351 / 3 =
x = 117 dribbles
500
Which is the better deal?
$1.99 / 7.2 = $0.28 --> 28 cents per ounce
$5.25 / 28.8 = $0.18 --> 18 cents per ounce
#2 is the better buy!
500
Halve 2/3 cup of sour cream
1/3 cup of sour cream
500
Double 2/3 cup of butter
4/3 cup of butter (1 and 1/3 cup)