# 40 Yard Dash -3Act Math

ACT 1:

This video was first brought to my attention from Dan Meyer’s My Opening Keynote for CUE 2014.  Turn the volume on mute when you show this to your students.  I also do not show the individual run, I start the video 15 seconds in.  I show the clips of Jacoby Ford and Terrence Cody ending at a minute in.

What questions do you have when you watch this video?

Ask students to write down their questions, I normally ask students to find at least 3.  When I observe that most students have questions written, I ask them to share those questions with their neighbor.  I then throw up a Microsoft Word document and start typing down questions students supply.  Students from my classroom came up with all sorts of different questions, some we can easily answer and others that we can’t.  I am looking for a key question or questions to start this lesson.  If students do not ask one of these questions, I tell them that I hope I can answer most of the questions provided, but that I need them to consider one of these questions first.

• How fast are they running?
• How much of a lead does Rich get on run 2?  run 3?
• How much does Rich lose by each time?
• How big of a lead does Rich need to tie? to win?

Any of these type of questions will lead students down the inquiry I hope to explore with them.

ACT 2:

Once again, this video can create a few different paths of exploration.  We can explore:

• The rate of the runners
• Graphs of the runners
• Equivalent equations

These are all excellent topics and students generate a lot of classroom discourse discussing each one.

1. Rates:  This is one that creates a lot of arguments about precision.  Students normally start trying to time Rich by using the clock on the wall, or their wrist watch.  Some will break out the stopwatch feature.  I have other students use the watch feature on their phones.  Timing issues like accuracy starting or stopping the time, cause quit a disturbance with the students.
2. Graphs: I love this part.  I normally show a clip twice and have students graph the race.  Independent and Dependent variables, scale factor on axis, and the solution of two lines are great topics to discuss.  Students really enjoy graphing the races and are really good at evaluating work and refining the process and answer.
3. Equations:  This normally involves at least one of the first two processes and builds upon that.  Finding the rate of each runner (their slope) and setting their expressions equal to each other leads to when Rich is overtaken.  Having these expressions will also allow us to find the exact time Rich is passed and how much of a head start he would need to either tie or finish first.  I can’t think of a better introduction into solving systems of equations.

ACT 3:

I normally show the opening video to answer how fast Rich runs, and turn up the volume to allow students to know how much of a head start he is given in the other races.

Extensions:

Show them the 3 man race (1:10 into the video) and let them loose, it’s fun to watch.