Clip 3/20: Multiplying and Factoring Polynomial Expressions Lesson Part 1A

Overview

Melissa Nix begins her work with her eighth-grade students with a mental math number talk, inviting students to share their strategies. She shows a slide with “12 x 15” on it, and asks students to show her they have an answer with a “quiet thumb” on their chest.

She challenges students to try to find a second strategy, and if so, to indicate it through a second finger on their chest. She asks students to share the answers they’ve found; all students deduce 180, but they apply different strategies for arriving at the answer. Melissa writes down students’ strategies on the board. Students identify that the strategy used by many was the distributive property.

Teacher Commentary

I want my students to start making predictions and connections and observations because that's when it becomes more relevant to them. I don't want them to be passive learners. I don't want to just show them that, “This is how you've derived it,” as formula. I want to actually let them experience it … even the formula of when you're graphing a parabola: what a maximum and a minimum is, and how velocity affects the height of that, and that all things actually fall in an arc, in a parabolic arc.

Just trying to wrap my own head around it, having memorized this formula to actually then applying it, I was throwing stuffed animals in the air in my classroom, to say, "No, look, here's our class mascot, our cow, right, and I'm going to throw and you watch where the maximum is."