Comparing Unit Rates

Unit Rates

Lesson 1

Ratios

A ratio compares the relative sizes of two quantities.

What is the ratio of rolled oats to sesame seeds?

Multiple Select

What is the ratio of dried cranberries to mixed nuts?

• 1 to 2

• 2:1

• 1/2

• 2 to 1

A rate compares two quantities with DIFFERENT units.

Driving 120 miles in 2 hours

The units are miles & hours

Multiple Choice

Which is a rate?

• $$\frac{2\ \ feet}{6\ \ feet}$$ "2 feet to 6 feet"

• $$\frac{4\ cups}{8\ cups}$$ "4 cups to 8 cups"

• $$\frac{10\ words}{30\ \sec onds}$$ "10 words in 30 seconds"

A unit rate is a rate that is simplified so that it has a denominator (2nd #) of 1 unit.

Driving 60 miles in 1 hour or 60 miles/1 hour

/ = "per"

Multiple Choice

Which is a UNIT rate?

• 100 miles / 3 hours

• 35 miles / 1 hour

• 70 miles / 2 hours

In order to simplify and find the unit rate: ALWAYS divide both numbers by the second number!

Multiple Choice

How do you simplify a unit rate?

• Divide by the second number.

• Multiply both numbers together.

• Add the two numbers together.

• Subtract the second number.

Multiple Choice

Find the unit rate (how many avocados per bag):

42 avocados in 7 bags

• 7 avocados/bag

• 6 avocados/bag

• 7 bags/avocado

• 14 avocados/bag

Multiple Choice

Find the unit rate (how many minutes per video):

24 minutes to watch 4 videos

• 4 minutes/video

• 4 videos/minute

• 6 minutes/video

• 8 minutes/video

A car travels 0.75 miles every minute. How can we use this information to find out how far the car travels in one hour?

The ratio of girls to boys in a classroom is 3:5. Kevin says there must be 8 students in the classroom. Which explains whether Kevin is correct?

• A. Kevin is correct because 3 girls + 5 boys = 8 students.

• B. Kevin is correct because 5 girls + 3 boys = 8 students.

• C. Kevin is incorrect because 3:5 may be a simplified ratio.

• D. Kevin is incorrect because the ratio 3:5 does not compare different units.

One pound of grapes costs $1.55. Which equation correctly shows a pair of equivalent ratios that can be used to find the cost of 3.5 pounds of grapes?

Multiple Choice

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