Lesson 3.2Comparing Unit Prices (Best Buy)
Start hereWords, worked example, and sentence starters
Learning target I can describe a rate using its two different units and use a model to find a travel time, and I can find a unit rate to compare prices and decide the better buy.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| Rates and Unit RatesSpanish: Tasas y tasas unitarias | A rate compares different units; a unit rate compares a quantity to 1 unit. | 180 miles in 3 hours = 60 miles per 1 hour. |
| RateSpanish: Tasa | A ratio comparing two amounts with different units, like miles per hour. | $12 for 4 games is a rate |
| Unit RateSpanish: Tasa unitaria | A rate for just 1 of something, like cost for 1 item. | $3 per 1 game |
| PerSpanish: Por | For each one. Example: 5 dollars per book. | 60 miles per hour means 60 miles for every 1 hour |
| RatioSpanish: Razón | A way to compare two amounts, like 3 to 2. | 5 to 3 or 5:3 |
| Unit priceSpanish: Precio unitario | A unit rate that gives the cost of exactly 1 item, like $0.60 per game. | $1.75 per pound |
How it worksWorked example
These numbers are not on your problems. The steps are. Follow them with your own numbers.
Store A sells 5 notebooks for $7.50. Store B sells 8 for $10.40. Which is the better buy?
- A: $7.50 ÷ 5 = $1.50 per notebook.
- B: $10.40 ÷ 8 = $1.30 per notebook.
- $1.30 < $1.50. Store B saves $0.20 per notebook.
Answer: Store B
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The unit price of is per .
- is the better buy because .
- You cannot compare the total prices because .
- The savings per is .
Word bank unit pricebetter buycomparetotaldividelowerhigherless thangreater thanpersaveeach
Watch out!A common mistake
A common mistake in Rates and Unit Rates is comparing total costs instead of unit rates: a student sees Pack X at $4.00 for 10 tokens and Pack Y at $6.00 for 16 tokens and picks Pack X just because $4.00 is the smaller number, without dividing to find the cost per token ($0.40 for Pack X vs. $0.375 for Pack Y
Lesson 3.2Comparing Unit Prices (Best Buy)
Apply Day · Version ASupported practice
Learning target I can describe a rate using its two different units and use a model to find a travel time, and I can find a unit rate to compare prices and decide the better buy.
-
1Complete each step, then write the final answer.
A booth charges $12 for 4 games. What is the cost for 1 game?
Show your workHint Divide the cost by the number of games.
Final answer: -
2Complete each step, then write the final answer.
A pack of 4 stickers costs $1. What is the cost for 1 sticker?
Show your workHint Divide the cost by the number of stickers.
Final answer: -
3Complete each step, then write the final answer.
Kim walks 6 miles in 2 hours. She walks at the same speed. How many miles does she walk per hour?
Show your workHint Divide the miles by the hours.
Final answer:
Lesson 3.2Comparing Unit Prices (Best Buy)
Apply Day · Version BCore practice
Learning target I can describe a rate using its two different units and use a model to find a travel time, and I can find a unit rate to compare prices and decide the better buy.
-
1Circle the letter of the best answer. Show how you know.
Compare both booths at 10 games. Booth A charges $4 for 5 games. Booth B charges $6 for 10 games. Which booth is the better buy?
- ABooth B — $0.60 per game
- BBooth A — $0.80 per game
- CBooth A — it costs less in all
- DThey cost the same per game
Show your work -
2Complete each step, then write the final answer.
A cyclist rides 36 miles in 3 hours at the same speed. How many miles does she ride per hour?
Show your workFinal answer: -
3Complete each step, then write the final answer.
A booth charges $7 for 4 games. What is the cost for 1 game?
Show your workFinal answer:
Lesson 3.2Comparing Unit Prices (Best Buy)
Apply Day · ChallengeExtension
Learning target I can describe a rate using its two different units and use a model to find a travel time, and I can find a unit rate to compare prices and decide the better buy.
-
1Circle the letter of the best answer. Show how you know.
Booth A charges $3 for 5 games. What is the unit rate in dollars per game?
- A$0.30 per game
- B$0.60 per game
- C$1.67 per game
- D$15.00 per game
per 1 -
2Circle the letter of the best answer. Show how you know.
Booth X charges $8 for 10 games. Booth Y charges $10 for 16 games. Mo says Booth X is the better buy because $8 is less than $10. Which booth is the better buy?
- ABooth Y — $0.625 per game
- BBooth X — $0.80 per game
- CBooth X — it costs less in all
Show your work -
3Complete each step, then write the final answer.
A plane flies 1,500 miles in 3 hours. It keeps the same speed. How many hours does it take to fly 2,500 miles?
Show your workFinal answer: