The Shower v Bath activity from Dan Myers’s Three-Acts Math tasks is about which one is cheaper, a shower or a bath. The first video shows a person taking a shower and a person taking a bath in order to set up the scenario. Then in part two it shows two videos, one showing the duration of the bath and shower, and one showing the time it takes to fill up to a gallon of water for both. Also in act two It tells you the cost of water in Mountain View, CA. In the last act the students answer questions based on the information they are provided. They have to figure out which one is cheaper, how long of a shower would they have to take to equal the same amount of water as a bath, and they will have to compare with their classmates.

http://mrmeyer.com/threeacts/showervbath/

The common core state standard for this activity is:

CCSS.MATH.CONTENT.6.RP.A.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.

To achieve the common core standard I would fist show my students the fist video of the person showering and taking a bath. I would then ask my students to predict what they thought the cheaper option was and why. This will get my students thinking about the problem of which option uses more water and which option is more expensive. Next I would ask my students what information they needed to solve the problem. After discussing this and coming to an answer I will then show my students the other two videos about the duration of the shower/bath and the water rate in minutes per gallon. This will help students reason and problem solve about a real world situation using mathematics.

Question 3-6 will be a good formative assessment to see if my students have achieved the learning target. These questions will get my students thinking and using their mathematical reasoning about this real world situation. The last question asks students to compare their data with their classmates. This will get my students creating charts, diagrams, averages, and generalizing the whole real world situation. This question will help show me that my students have met the learning target.