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.

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What Do You Do with a Dizzy Sailor?

CAMI often goes back and forth between problems that challenge us as problem-solvers and those which we could use to develop problem-solving in our students. At this meeting, Solange bridges the divide and does both.

Solange led us in an exploration of two problems – first, the Dizzy Sailor Problem and then the Perimeter of 18 Problem. The former was to challenge and deepen our own problem-solving. The latter was to have a discussion about how some of the math from the dizzy sailor connects to the perimeter of 18, which we all agreed was a problem we could do with our students. Continue reading “What Do You Do with a Dizzy Sailor?”

Carl’s Basketball Problem

With a simple set up, CAMI enters a rabbit hole of notice/wonder and number patterns.

At our meeting, we worked on two tasks that I got last summer at a gathering of teachers from the K-12 system called NYC Twitter Math Camp.

The first is an activity teachers can use to develop group problem-solving norms with students. Continue reading “Carl’s Basketball Problem”

Gerrymandering Math

Can math save us from dark depression?

Among the thoughts racing through our minds on election night was the realization that we had decided to have a CAMI meeting on the next day. What were we thinking? Solange and I spoke before the meeting. We briefly considered scrapping our plans to explore gerrymandering math and do something to get our minds off the election, but eventually decided that we should take the opportunity to talk with other teachers about this moment. Continue reading “Gerrymandering Math”

CAMI Roadshow: NCTM 2016

CAMI celebrated its two year anniversary with a few founding CAMI members representing our teachers’ circle at this year’s regional NCTM conference in Philadelphia.

Our session began at 8 in the morning with a small but energetic and enthusiastic group of teachers from Maryland and New Jersey. We started with introductions and a brief introduction to CAMI including a discussion of the Diana Lambdin quote that went out with our initial invitation to CAMI in November 2014… Continue reading “CAMI Roadshow: NCTM 2016”

Dana’s Rectangle

Inspired by the work of the Navajo Math Circle, CAMI explores the area of rectangles and their borders, testing conjectures and making generalizations.

Eric started the meeting by talking about the Navajo Math Circles, which is a joint project of the Navajo Nation and mathematicians from Math Teachers Circle Network. A recent documentary tells the story. This meeting’s problem is from an article about the Navajo Math Circle (see Further Reading pdf link above) by Tatiana Shubin, whose video Grid Power was the subject of this past July’s CAMI meeting.

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The Lawn Mower Problem

What happens when we let students write the questions?

Tyler opened the meeting by giving us a situation adapted from one he’d seen on Twitter posted by Fawn Nguyen. He then asked two questions: What do you notice? What do you wonder? Continue reading “The Lawn Mower Problem”

Grid Power

What mathematical questions can you ask of a blank piece of grid paper?

After CAMI was recently accepted as a member of the Math Teachers’ Circle Network, a few of us started exploring their resources, which include a series of videos of mathematicians leading teacher circles. Eric was inspired to share today’s problem after watching Tatiana Shubin’s Grid Power.

Eric started the meeting by asking participants to look at a blank piece of graph paper for 7 minutes and write down questions that came up. 7 minutes?! Yes, 7 minutes. Continue reading “Grid Power”

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”

Millions and Billions

I need your help visualizing millions and billions.

In a recent interview on Innovation Hub, the mathematician and educator Steven Strogatz reflected on math education (specifically the requirement for students to study algebra) and the level of number in the general public:

“We don’t do a very good job of teaching what you might think of as numeracy, that is, the use of arithmetic [in the real world]. So, here’s an example: In current political discussion, there is a lot of talk from Senator Sanders about millionaires and billionaires, right? Continue reading “Millions and Billions”