Lesson 3.93.9 · Part II
Start hereWords, worked example, and sentence starters
Learning target I can find and check equivalent ratios using multiplication and division.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| Equivalent RatiosSpanish: Razones equivalentes | Ratios that compare quantities in the same relationship. | 2:3 = 4:6 because both parts were multiplied by 2. |
| RatioSpanish: Razón | A way to compare two amounts, like 3 to 2. | 3 red apples : 5 green apples |
| RateSpanish: Tasa | A ratio comparing two amounts with different units, like miles per hour. | 60 miles per 1 hour |
| ProportionSpanish: Proporción | A math sentence saying two ratios are equal. | 2/3 = 4/6 |
| SimplifySpanish: Simplificar | To write a ratio with smaller numbers that still compares the same way. 6:8 and 3:4 are the same ratio. | 12:18 → divide both by 6 → 2:3 |
| Ratio tableSpanish: Tabla de razones | A table of equal ratios that shows a pattern. | Cups of juice: 2, 4, 6 | Cups of water: 3, 6, 9 |
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
Word bank Equivalent RatiosRatioRateProportionSimplifyRatio table
Watch outA common mistake
A common mistake in Equivalent Ratios is ADDING the scale factor to one part instead of MULTIPLYING both parts by it. For example, scaling 2:5 by a factor of 4 should give 8:20 (2×4 and 5×4) — not 6:9 (2+4 and 5+4). Adding changes the taste of the recipe (and the value of the ratio); only multiplying or dividing both numbers by the same amount keeps it equivalent.
Lesson 3.93.9 · Part II
Apply Day · Version ASupported practice
Learning target I can find and check equivalent ratios using multiplication and division.
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1Complete each step, then write the final answer.
A ratio is 1:4. Multiply both numbers by 3. The new ratio is 3 : ?. What is the missing number?
Show your workHint Multiply the second number by 3: 4 × 3.
Final answer: -
2Complete each step, then write the final answer.
A ratio is 3:2. Use a scale factor of 5. The new ratio is ? : 10. What is the missing number?
Show your workHint Multiply the first number by 5: 3 × 5.
Final answer: -
3Complete each step, then write the final answer.
A recipe uses 2 cups of rice for 3 cups of water. You use 12 cups of rice. How many cups of water do you need?
Show your workHint What times 2 makes 12? Multiply the water by the same number.
Final answer:
Lesson 3.93.9 · Part II
Apply Day · Version BCore practice
Learning target I can find and check equivalent ratios using multiplication and division.
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1Complete each step, then write the final answer.
Jay adds 2 to each number in 2:3 and gets 4:5. He says they are equivalent. Find the correct ratio 4 : ?. What is the missing number?
Show your workFinal answer: -
2Complete each step, then write the final answer.
Is 20:8 equivalent to 25:10? Type yes or no.
Show your workFinal answer: -
3Complete each step, then write the final answer.
A ratio is 5:2. Multiply both numbers by 4. The new ratio is 20 : ?. What is the missing number?
Show your workFinal answer:
Lesson 3.93.9 · Part II
Apply Day · ChallengeExtension
Learning target I can find and check equivalent ratios using multiplication and division.
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1Circle the letter of the best answer. Show how you know.
Solve the proportion 4/10 = x/25 for x.
- A8
- B10
- C19
- D62.5
Rewrite each fractionWork it outSimplify -
2Complete each step, then write the final answer.
Lia says 9:12 and 12:15 are equivalent, because both numbers went up by 3. Find the number that makes 12 : ? equivalent to 9:12.
Show your workFinal answer: -
3Complete each step, then write the final answer.
The ratio 8:14 is equivalent to 12 : ?. Find the missing number.
Show your workFinal answer: