Instructional Activity# Water Tanks

Lesson 9. Unit 4. Grade 8 Open Up Resources

Open Up Resources10 min(s)

This Instructional Activity is a part of the Lesson 9, Unit 4, Grade 8. The goal of this activity, and the two that follow, is for students to solve an equation in a real-world context while previewing some future work solving systems of equations. Here, students first make sense of the situation using a table of values describing the water heights of two tanks and then use the table to estimate when the water heights are equal. A key point in this activity is the next step: taking two expressions representing the water heights in two different tanks for a given time and recognizing that the equation created by setting the two expressions equal to other another has a solution that is the value for time, t, when the water heights are equal.