Lesson 3.9Equivalent Ratios
Set B · Version ASecond form · supported practice
Learning target I can find and check equivalent ratios using multiplication and division.
Why This Matters Chef Montoya is preparing her famous tomato soup for a school banquet. Her original recipe serves 8 people, but tonight she needs to serve 32 guests. She needs your help to scale the recipe without changing the flavor!
RememberEquivalent Ratios
Proportions & Equivalent Ratios. Formula: a/b = c/d Equivalent ratios are ratios that mean the same thing. You make one by multiplying or dividing BOTH numbers by the same amount.
- Two ratios are equivalent if their simplified forms or cross products are equal.
- Find the scale factor between corresponding terms.
- Multiply or divide to solve for the missing term in the proportion
Words: Equivalent Ratios (Razones equivalentes)Ratio (Razón)Rate (Tasa)Proportion (Proporción)Simplify (Simplificar)
-
1Circle the letter of the best answer. Show how you know.
A printer prints 30 pages every minute. How many pages does it print in 4 minutes?
- A7.5 pages
- B30 pages
- C34 pages
- D120 pages
Show your work -
2Circle the letter of the best answer. Show how you know.
A faucet fills 3 gallons every 2 minutes. How long does it take to fill 18 gallons?
- A6 minutes
- B9 minutes
- C12 minutes
- D36 minutes
Show your work -
3Circle the letter of the best answer. Show how you know.
A recipe uses 3 cups of flour for 12 muffins. How much flour is needed for 20 muffins?
- A2.4 cups
- B4 cups
- C5 cups
- D6 cups
Show your work -
4Circle the letter of the best answer. Show how you know.
Store A sells 5 notebooks for $6.25. Store B sells 8 notebooks for $9.60. Which store has the lower price per notebook?
- AStore A
- BThey are equal
- CYou cannot tell
- DStore B
Show your work -
5Circle the letter of the best answer. Show how you know.
A local smoothie shop sells a Berry Blast smoothie. The recipe calls for 2 cups of strawberries for every 3 cups of yogurt. Today they need to make 15 cups of yogurt worth of smoothies for a catering order. What is the scale factor from 3 cups of yogurt to 15 cups?
- A3
- B5
- C12
- D45
Show your work -
6Circle the letter of the best answer. Show how you know.
A local smoothie shop sells a Berry Blast smoothie. The recipe calls for 2 cups of strawberries for every 3 cups of yogurt. Today they need to make 15 cups of yogurt worth of smoothies for a catering order. How many cups of strawberries are needed?
- A5
- B10
- C12
- D15
Show your work
Explain your thinkingHow did you find the missing values in Chef Montoya's table? How can you PROVE two of your rows are equivalent ratios?
Sentence starter I multiplied ___ and ___ by the same number, ___, so the ratio ___ is equivalent to 3:2.
Lesson 3.9Equivalent Ratios
Set B · Version BSecond form · core practice
Learning target I can find and check equivalent ratios using multiplication and division.
Why This Matters Chef Montoya is preparing her famous tomato soup for a school banquet. Her original recipe serves 8 people, but tonight she needs to serve 32 guests. She needs your help to scale the recipe without changing the flavor!
-
1Write the letter of the matching item on each line.
Match each recipe ratio to a batch that tastes exactly the same.
- 2:3
- 3:5
- 4:7
- 5:6
- A8:12
- B9:15
- C12:21
- D10:12
-
2Write the name of the correct group on each line.
The recipe ratio is 2 cups flour to 5 cups milk (2:5). Sort each batch: does it taste the same (equivalent) or not?
- 4:10
- 6:15
- 8:20
- 4:9
- 2:7
- 5:2
-
3Circle the letter of the best answer. Show how you know.
A local smoothie shop sells a Berry Blast smoothie. The recipe calls for 2 cups of strawberries for every 3 cups of yogurt. Today they need to make 15 cups of yogurt worth of smoothies for a catering order. Why must both ingredients be multiplied by the same factor?
- ABecause 2 and 3 are both small numbers
- BBecause addition would be harder
- CSo the total is a whole number
- DSo the ratio stays 2:3 and the smoothie tastes the same
Show your work -
4Circle the letter of the best answer. Show how you know.
Chef Montoya's dressing uses 3 spoons of oil to 4 spoons of vinegar (3:4). Which recipe card shows an EQUIVALENT ratio?
- A3:8
- B4:3
- C6:7
- D9:12
Show your work -
5Circle the letter of the best answer. Show how you know.
The lemonade station mixes 5 cups of lemon juice to 2 cups of sugar (5:2). Which batch keeps the SAME taste?
- A5:4
- B7:4
- C10:6
- D15:6
Show your work
-
6Find the mistake. Explain it, then show the correct work.
Level 2 Extension — The Scaled-Up Pancake Batter
- 1Set up the ratio3 cups flour : 8 cups water = ? : 24 cups water
- 2Find the multiplier24 ÷ 8 = 3
- 3Apply to the flour3 + 3 = 6
- 4Answer6 cups flour : 24 cups water
Which step has the mistake? Explain what went wrong, then show the correct work.
Correct workCorrect answer: