Figure 10: Video of class discussion from Say It With Symbols

Problem 1.1 from Say It With Symbols introduces students to equivalence of algebraic expressions. Students produce several different, but equivalent expressions. While validating each expression, the class finds that one is not correct. Students draw on their knowledge from previous units to show why.

Lappan, G., Phillips, E. (2009) A Designer Speaks. Educational Designer, 1(3).
Retrieved from: