4.2+Using+Unit+Rate+0910

 Big Idea Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.

Mehreen Matin M.M 1/12/09

Problem 4.2 - Using Unit Rated When Madeline and Luis compared the fuel economy of their new cars, they found these rates:

Luis's car went 452 miles with 15.5 gallons of gasoline
 * Madeline's car went 580 miles with 19 gallons of gasoline

****A. For each car, find a unit rate describing the mileage. Which car got better gas mileage? In other word which car went more miles per gallon of gas****.

Madeline drove 580m from Denver to Prichet and used 19 gallons of gas. Luis drove 452m from Denver to Monument Park and used 15 gallons of gas. Madeline had better gas because her car can go to 30 miles per gallon and Luis's car can go till 29 miles per gallon

****B. Complete the table below, showing the fuel used and the miles covered by each car based on the unit rates you found in part A. We call this kind of table a** //**rate table.** //
 * = Gallons of Gas ||= 0 ||= 1 ||= 2 ||= 3 ||= 4 ||= 5 ||= 6 ||= 7 ||= 8 ||
 * = Miles in Madeline's car ||= 0 ||= 30 ||= 60 ||= 90 ||= 120 ||= 150 ||= 180 ||= 210 ||= 240 ||
 * = Miles in Luis's car ||= 0 ||= 29 ||= 58 ||= 87 ||= 116 ||= 145 ||= 174 ||= 203 ||= 223 ||


 * C. Look at the patterns in your table. For each car write an equation for a rule you can use to predict the miles driven from the gallons of gas use****d

Madeline - m=30g Luis - m=29g

**D. Use the rules you wrote in part C to find the number of miles each car could cover if it used 9..5, 15.5, 19, 23.8, 100, 125 and 150 gallons of gasoline.

Madeline - : 9.5: 285m 15.5g: 465m 19g: 570m 23.8g: 714m 100g: 3000m 125g: 3750m 150g :4500m Luis - 9.5g: 275m 15.5g: 449m 19g: 551m 23.8g: 690.2m 100g: 2900m 125g: 3625m 150g: 4350m


 * Follow up

1. Use your data from B and D of the (gallons and miles) data for each car. Madeline's car: **

Luis's car:

2. How are your two graphs alike? How are they different?

They are different because there is a different constant rate for each graph and they are alike because they both increase at a constant rate.

3. What do you think makes the two graphs different? They are different because of the rate its going at.