Formative Assessment 39

Assessment Problem: 

Harold has some money. Sally has four times as much money as Harold. Harold earns $18.00 more dollars. Now he has the same amount as Sally. Can you figure out how much money Harold has altogether? What about Sally?

Common Responses: 

10 students out of 18 represented Harold’s initial amount as N, X or H and Sally’s amount as . 8 students correctly wrote N+18 to represent Harold earning $18 more.

Mathematical Issues: 

With scaffolding, students can model situations correcting with using equations.

Domain: 
Algebraic Relations
Theme: 
Modeling
Common Core Standards: 
A-CED: Create equations that describe numbers or relationships
Research References: 
Brizuela, B. M. & Schliemann, A.D. (2003). Fourth Graders Solving Equations. Medford, MA: Tufts University.