Multiple Ways of Multiplying

We explored multiplication through a number talk and alternative algorithms for calculating products.

Before the meeting, Davida showed Rachel and me a multiplication method a student had showed her earlier in the day. The student said that she only knew how to do multiplication using the method on the right and wanted to learn the method on the left. What a coincidence! This is exactly what I was planning to explore today.

Continue reading “Multiple Ways of Multiplying”

Making and Testing Conjectures: The Diagonal Problem

Draw a rectangle on grid paper and draw a diagonal. Is there a way to predict the number of squares the diagonal will pass through?

I have been thinking about MP3 from the Common Core, specifically about how to get students to make conjectures, to test those conjectures and to refine their conjectures when it turned out they were not always true. I was also thinking about student perseverance and helping them not get too frustrated. I’ve done some activities like Marilyn Burns’ consecutive sums problem (see additional resources below), but I want something that feels messier and a little more unwieldy. Continue reading “Making and Testing Conjectures: The Diagonal Problem”

Keep it in the Family (with Pythagorean Triples)

Many of us are familiar with the 3, 4, 5 right triangle, and maybe the 5, 12, 13. Do you know any others? Is there a pattern to these triples?

As we came in the room, Eric asked us to place a post-it with our name on a voting spectrum he’d drawn on the board, ranging from “Never” to “This morning” under the statement, “The last time I thought about multiplication”.

As we settled in, Eric shared his goals for the meeting. He’s been working on a lesson for students combining some work he’s been doing on area models with a problem that has been consuming him for weeks. Continue reading “Keep it in the Family (with Pythagorean Triples)”