Using Rates to Determine Efficiency

Characteristics of Rate

Formative Assessment

Summary of the Math: Characteristics of Rate

Read and Discuss

  • Fuel efficiency can be described using two rates: miles per gallon and gallons per mile. More miles per gallon means greater fuel efficiency; but fewer gallons per mile also means greater fuel efficiency.
  • Fuel efficiency in miles per gallon (mpg) is a rate. You will find mpg useful for finding how far you can go on any number of gallons of gas.
  • Fuel efficiency in gallons per mile (gpm) is also a rate. You will find gpm useful for finding how many gallons of gas you need to go any number of miles.
  • The smaller the rate in gpm, the greater the fuel efficiency.
  • The rates 20 mpg and 0.05 gpm describe the same situation. They both describe the relationship between 300 miles and 15 gallons.

Hint:

Can you do the following?

  • Explain what miles per gallon andgallons per mile mean.
  • Include the term rate .
  • Discuss how to define the fuel efficiency of a car.