Compare and Predict Rates and Ratios

Compare and Predict Rates and Ratios

Mrs. Cantu

How are rates and ratios similar and different?

• Ratios - a comparison of two quantities describing the same attribute

  Example: There are 8 boys and 9 girls in the classroom. The ratio is 8 to 9

• Rate - comparison of two quantities having different attributes

  rates are a special kind of ratio

  example: Your heart beats 80 beats per minute, you drive 15 miles/hour

• Unit Rate - has a denominator of 1 when written as a fraction

Multiple Choice

Thinking of equivalent ratios, 1 : 4 is equal to:

• 2 : 9

• 4 : 16

• 6 : 26

• 8 : 40

Multiple Choice

You spend $40 on 5 pounds of concrete. What is the unit rate in dollars per pound?

• $8 per pound
• $5 per pound
• $35 per pound
• 0.125 pounds per dollar

Example 1

STAAR Question - window washer cleaned 38 windows in 2 hours. At this rate, how many windows did he clean in 7 hours? 

Example 2

STAAR Question - In Dallas, Texas, 8 bats ate 40 grams of insects in one night. At this rate, how many grams of insects could 64 bats eat in one night? 

Multiple Choice

STAAR Question – The ratio of boys to girls in a choir is 5 to 4. There are 52 girls in the choir. How many boys are there?

• 65 boys

• 60 boys

• 75 boys

• 50 boys

Google Classroom

Open the assignment labeled Warm Up and Practice under January 6, 2021