Texas Instruments TI-73VSC Teachers Guide - Page 69

64 Using the TI-73: A Guide for Teachers ♦ Demonstrate to students how to measure a foot, from heel to toe, so that everyone is measuring the same. Ask: What unit should we use to measure? (inches) What if there are parts of an inch left? Will we record it as a decimal or fraction? (Fraction would probably be easiest for this part.) Do we need to measure both feet or just one foot? Should we measure with the shoe on or off? Activity Have students perform the steps unless otherwise indicated. 1. Have each student measure 20 people, or the number of people that the class decides to measure. Students need to decide how many adults and how many children they will measure. They may use the activity sheet provided to organize their data. 2. Once students have collected data, ask: What is an average? How will we find out if the average foot size in our survey is 12 inches, or a foot? (Add them all together and divide by the number of feet measured.) How will we add the fractional parts? (If you wish, you can convert them to decimals using the TI-73. See the example in the next step.) 3. Find the averages from the data. a. Go to the Home screen. - l b. Convert fractions to decimals by using the > key on the TI-73. Example To convert 12¼ inches to a decimal, enter Y Z < Y = Q > b. c. From the Home screen, find the mean using traditional methods. Probability and Statistics © 1998 TEXAS INSTRUMENTS INCORPORATED