# 8.10: Trip Functions

**Trip Functions – Complete Tables and Write Function Rules**

**Teacher Notes**

Students use facts to complete rate tables and write rules in words to describe the relationship between the input and the output. All functions are of the form of , that is, the sum of an initial value (number of miles showing on odometers/pedometers before the start of a trip) and the product of number of hours traveled and average speed in miles per hour.

**Solutions:**

**Trip Functions 1**

Rule: Number of miles is the sum of 23,500 and the product of number of hours and 40 mph.

**Trip Functions 2**

Rule: Number of miles is the sum of 72,160 and the product of number of hours and 30 mph.

**Trip Functions – Complete Tables and Write Function Rules**

**Read the facts. Follow the steps.**

**Facts:** Before the start of the cross-country trip, the odometer in Mrs. Wilson’s car showed 4,100 miles. On the trip, she averaged 50 miles per hour.

**First:** Complete the table to show changes in Ms. Wilson’s odometer for the first 6 hours.

**Second:** Write a rule that describes how the number of hours traveled is related to what the car odometer shows.

Rule: _______________________________________________________

**Trip Functions 1**

**Facts:** Before he left on his trip, Mr. Patterson’s truck odometer showed 23,500 miles. He averaged 40 miles per hour on his drive from Sacramento to San Diego.

**First:** Complete the table to show changes in Mr. Patterson’s truck odometer for the first 6 hours.

**Second:** Write a rule that describes how the number of hours traveled is related to what the truck odometer shows.

Rule: _______________________________________________________

**Trip Functions 2**

**Facts:** The Karene City School Bus averaged 30 miles per hour on its trip to the state basketball competition. At the start of the trip, the bus’s odometer showed 72,160 miles.

**First:** Complete the table to show changes in the bus’s odometer for the first 6 hours.

**Second:** Write a rule that describes how the number of hours traveled is related to what the bus odometer shows.

Rule: _______________________________________________________

*Extra for Experts:***Trip Functions – Complete Tables and Write Function Rules**

**Trip Functions Extra 1**

**Facts:** Charlie’s pedometer is on his belt. It registers the number of miles walked. Before the hike, the pedometer showed 27 miles. Charlie hiked for several days and averaged 3 miles per hour.

**First:** Complete the table to show changes in Charlie’s pedometer for the first 6 hours.

**Second:** Write a rule that describes how the number of hours traveled is related to what the pedometer shows.

Rule: _______________________________________________________

**Trip Functions Extra 2**

**Facts:** Before Brent left on his bike hike, his bike’s odometer showed 62 miles. Brent averaged 8 miles per hour.

**First:** Complete the table to show changes in Brent’s bike odometer for the first 6 hours.

**Second:** Write a rule that describes how the number of hours traveled is related to what the bike odometer shows.

Rule: _______________________________________________________

**Solutions:**

**Trip Functions Extra 1**

Rule: Number of miles is the sum of 27 and the product of number of hours and 3 mph.

**Trip Functions Extra 2**

Rule: Number of miles is the sum of 62 and the product of number of hours and 8 mph.