Formative Assessment 105

Assessment Problem: 

The “Ovens” Problem: A cook has to cook a large roast as quickly as possible.  The meat is at room temperature.  The cook has a conventional oven and a microwave oven.  In a cooking test it was found that during the cooking time, the temperature of the roast in the conventional oven is always higher than the temperature in the microwave and that the cooking time required in both ovens is exactly two hours.  In the microwave oven, the heat of the lamb increases at a constant rate, and in the conventional oven (kept in constant temperature), the heat of the roast increases at a changing rate.  Could the cook use the two ovens to reduce the two-hours cooking time?

Common Responses: 

Students quickly notice that they are given incomplete information. 

Mathematical Issues: 

This problem requires modeling without algebraic equations for students to work with. It is more of a “big picture problem” that students must be somewhat creative to solve.

Patterns & Functions
Common Core Standards: 
7.EE: Expressions and Equations
Research References: 
Yerushalmy, M., Shternberg, B., & Gilead, S. (1999). Visualization as a Vehicle for Meaningful Problem Solving in Algebra. . Paper presented at the Conference of the Psychology of Mathematics Education.