Shower v. Bath

The 3-acts math task, “Shower v. Bath,” by Dan Meyer can be found at http://mrmeyer.com/threeacts/showervbath/.

This activity is aligned to:

• CCSS-Math 6.RP.3: Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.

The first act is a split screen video of a guy sitting in the bath on the bottom part of the screen and him standing in the shower in the top part of the screen.  Underneath the video, there is a question: “which do you think is cheaper: a shower or bath? Why?” The second act has a video of the duration of the shower and bath. The guy takes a shower in about 2 minutes and 24 seconds and takes a bath in about 8 minutes and 10 seconds.  There is also a video of the water rate in minutes per gallon for the bath and the shower.  It takes the faucet for the bath only about 11 seconds to fill up a one-gallon jug and it takes the shower head about 27 seconds.  Then under the videos there is an image of the cost of water in Mountain View, CA.  The third act has four questions: “how would the situation have to change for the answer to reverse itself,” “how long of a shower can he have with the same amount of water he used for the bath,” “which is cheaper for you? Collect data on your own shower and bath usage,” and “which is cheaper for your class? Average the data from all your classmates.”

For the lesson, I would introduce the activity by showing my students the first act video and ask them which they think would be cheaper. A good way for the students to actively participating in the activity is to give each of the students white boards. This way they can write either bath or shower and hold up their prediction and I can choose a few students to explain why they chose their prediction.  This will get the students thinking what option would use more water and what factors go into figuring out this problem. I will have the students brainstorm what information they are going to need in order to be able to get an answer in the end. From here I will show the video of how long it takes for the man in the video to shower and bathe and how long each option takes to fill up a gallon jug. This will be a good problem for the students to really think and work through the problem.

I will formally assess the students by having each student create a small poster with comparing their data to their classmate’s data. This will have the students making graphs, charts, finding averages, and making comparisons. From the poster, it will be clear if they met the learning target.