This is a guided inquiry activity through which students will discover how to calculate the "Least Common Multiple" through an application problem involving pit-stops during the Indy 500 car race.
Students will watch a brief 2 minute video (link included) of the last lap of the 2011 Indianapolis 500. Following the video, the students are prompted through a PowerPoint slide to answer a couple of questions about the race cars making fuel stops and tire stops on specific laps. This activity culminates in the students determining the Least Common Multiple for the fuel stops and the tire stops (on which pit stops with the car need both fuel and tires) which serves as great lead up activity to finding common denominators and writing equivalent fractions.
I conduct this activity at the beginning of class on the day that I teach writing equivalent fractions (for addition and subtraction with unlike denominators). I typically let the students work in pairs or groups of three and the activity itself usually takes between 10 and 15 minutes. My students (middle school age) love the video (which I project on the screen) and the excitement of the driver just about to win. After the students work through the questions and the find the least common multiple, I immediately show them how to write equivalent fractions using their pit stop lap numbers as the denominators.
You are purchasing a 3 slide PowerPoint 2010 file. Feel free to modify the questions to fit your students needs and abilities!