Early algebra ideas about binomial expansion, Stephanie's interview four of seven, Clip 2 of 9: Reviewing the algebraic expansion of (a+b) cubed.

In the second clip in a series of nine from the fourth of seven interviews in which 8th grader Stephanie explores Early Algebraic Ideas about Binomial Expansion, Stephanie describes to researcher Carolyn Maher her algebraic expansion of (a+b) cubed. Stephanie first rewrites the expression as (a+b)(a+b)(a+b), then replaces two factors of (a+b) with the quantity (a squared + 2ab + b squared) and uses the distributive property to complete the expansion which she then simplifies. The problem as presented to Stephanie: Explain your conclusions about the cube of the quantity (a+b).Transcript and student work are also available.Robert B. Davis Institute for Learning. (1996). Early algebra ideas about binomial expansion, Stephanie's interview four of seven, Clip 2 of 9: Reviewing the algebraic expansion of (a+b) cubed. [video]. Retrieved fro