Formative Assessment 128

Assessment Problem: 

In grandmother Rachel’s jam factory, jam is made out of sugar and fruit. Grandmother Rachel mixed 300 kilograms of jam containing 30% of sugar
with 700 kilograms of jam containing 20% of sugar. What percentage of sugar does the new mixture contain?

Common Responses: 

There is not a common response, rather students tend to try multiple methods and generally become lost in the process.

Mathematical Issues: 

It is sometimes difficult to find problems that create true dilemmas for students. This problem creates the dilemmas through conversation with an interviewer as the learner interprets the problems in a verbal exchange.

Domain: 
Modeling & Word Problems
Theme: 
Conceptual understanding through word problems
Common Core Standards: 
7.EE: Expressions and Equations
Research References: 
Cifarelli, V. (1991). Conceptual structures in mathematical problem solving. Paper presented at the annual meeting of the American Educational Research Association, Chicago, IL.