1. Proportions and Measurement Systems Review the English measurement system and the metric system Convert measurement units using conversion factors Convert measurement units using dimensional analysis Learn and use the term rate

2. Have you traveled to another country? Have you ever converted money when you have traveled? Have you purchased gasoline by the liter? How does it compare to buying it by the gallon?

3. Converting Centimeters to Inches Materials Needed Metric Measuring Tape Feet-Inches Measuring Tape Template for collecting data Communicators

4. Converting Centimeters to Inches In this investigation you will find a ratio to help you convert inches to centimeters and centimeters to inches. Then you will use this ratio in a proportion to convert some measurements from the system standard in the U.S. to measurements in the metric system and vice versa.

5. Measure the length and/or width on each of six different sized objects. Record the inch measurement and the centimeter measurement in a table.

6. Enter the measurements in inches into your calculator’s list L1 and the measurements in centimeters into list L2. Into list L3 enter the ratio of centimeters to inches, L2/L1, and let your calculator fill in the ratio values. How do the ratios of centimeters to inches compare for the different measurements? If one of the ratios is much different from the others, recheck your measurements.

7. Choose a single representative ratio of centimeters to inches. Write a sentence that explains the meaning of this ratio. My ratio of centimeters to inches means...

8. Using your ratio, set up a proportion and convert each length. 215 centimeters = x inches 1 centimeter = x inches 1 inch= x centimeters How many centimeters high is a doorway that measures 80 inches? Using your ratio, set up a proportion and solve for the requested value. y centimeters = x inches. Solve for y. c centimeters = i inches. Solve for i.

9. Jonas drove his car from Montana to Canada on vacation. While there, he needed to buy gasoline and noticed that it was sold by the liter rather than by the gallon. Use the conversion factor at the right to determine how many liters will fit in his 12.5 gallon gas tank. Record your solution on your Communicator®. 1 gallon = 3.79 liters

11. This cable car goes from one peak on Whistler Mountain to another peak. The cable car or gondola is moving at a rate of 24.6 feet per second. How fast is this in miles per hour?

12. A radio-controlled car traveled 30 feet across the classroom in 1.6 seconds. How fast was it traveling in miles per hour? Write a ratio for the speed of the car in feet per seconds. Record this on your Communicator®.

13. Since multiplying by 1 does not change the value of a number or ratio you can multiply by a conversion factor that equals one.