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7th Grade Math / Lesson 5: Unit Rate

UNIT RATE
What will we be learning in this lesson?


  • In this lesson, you will learn how to make comparisons of unit rates to determine which of the given situations would be the better buy.

    Vocabulary words are found in this purple color throughout the lesson. Remember to put these in your notebook.


UNIT RATE


  • When people shop, they often find different quantities of items being sold at different prices.
  • Comparison shopping can help someone find which would be the best buy.
  • Comparison shopping uses proportional thinking. It involves finding the unit price (rate) of the items in question.
  • Suppose the store was selling a bag of apples for $3.50. There are 10 apples in the bag. How much does each apple cost?
  • Finding the price of each apple is finding the unit rate of the apples.
  • When talking about shopping, a unit rate is the price per item.


UNIT RATE


  • Suppose the store was selling a bag of apples for $3.50. There are 10 apples in the bag. How much does each apple cost?


  • Here is the proportion to use to find the unit rate of the apples.

  • Remember, multiply on the diagonal, then divide by the other number.

    3.50 * 1 = 3.50 / 10 = .35

    The cost of each apple in the bag is $.35


UNIT RATE


  • To find the best buy, you need to compare the unit prices of both quantities and decide which is better.
  • Two boxes of the same cereal, one is $1.79 for 10 ounces and the other is $2.09 for 13 ounces. Which is the better buy?
  • Find the unit price for each of these quantities.


  • Can you determine which is the better buy after comparing the unit prices

  • Be sure to go back to your classroom to get any homework assignments or other activities you need to attend to.