Sarah’s Passing Drill

In another edition of revisiting problems from the CAMI vaults, at this month’s meeting we went back to further explore a number pattern we first looked at in January 2017 (Carl’s Basketball Problem).

We started off discussing WHAT IS SIMILAR? WHAT IS DIFFERENT? looking at these four expressions:

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Diagonals in Rectangles

2024 marks the 10th anniversary of CAMI (!) and to honor all we have learned and all the ways we have grown as a group, we are going into the vaults for a few CAMI meeting, to reopen and revisit some of our early explorations together. This month’s meeting was a new take on a problem we explored in June 2016 at Making and Testing Conjectures: The Diagonal Problem.

We started with a Which One Doesn’t Belong?

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Factor Graphs

Sarah Lonberg-Lew of the Adult Numeracy Network and SABES joined us from Gloucester, MA to lead this meeting with me (honestly, I did very little). We explored a diagram that Play With Your Math calls factor graphs. They got the idea from Things to Make and Do in the Fourth Dimension, by the mathematician and educator Matt Parker. (Check out Numberphile for some of his videos.)

The week before the meeting we sent out this teaser:

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Playing with Prime Factors

Starting with a colorful visual representation of numbers, we looked at a series of problems based on prime factors.

For the last few months, I’ve been working on study materials on exponents and roots. While doing research for the packet, I started to get interested in factors and especially prime factors. It turns out that they are really useful for thinking about lots of different kinds of math that we have been looking recently. For example, the mathematics of bicycle gears or Spirograph both have to do with factors, as do fractions, place value, exponents and other math that is relevant to math teaching in adult literacy.

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A Strange Algorithm

In our first evening meeting, Eric shared a web site that turns pairs of numbers in diagrams. But how does it work?

(This meeting was based on an underground mathematics lesson, Fawn Nguyen’s post and Michael Lawler’s videos. Thank you all!)

I started the meeting by showing the group the Picture This! web site that turns pairs of numbers into a diagram visualization. I asked for a volunteer to give me two numbers, each less than 10. The first suggestion was 3 & 7. I entered the number into Picture This and this diagram was returned.

3 & 7

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Factor Towers

Eric shared activities from a draft lesson on factors, multiples, primes and composites. The lesson is linked in the post if you are interested in using the materials from the meeting. He would love feedback if you use it with a class.

Launch

To start off the meeting, Eric put us into groups and gave each group a bag of paper tiles. He asked us to spend a few minutes looking at them and discussing anything we noticed.

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Multiple Factors

Several engaging activities for exploring factors. Which would you use for HSE math classes and how would you use them?

I puzzled over what to bring to today’s meeting for days. I have a couple unfinished problems that I’ve been thinking to bring to a CAMI meeting, but in the end I chose to go with a few activities on factors, mostly from Fostering Algebraic Thinking, by Mark Driscoll. A group of us read the book last summer and loved the problems. There were so many good ones that we weren’t able to solve them all while reading the book. I went into this meeting hoping that the surprise of the central problem wouldn’t be ruined. Continue reading “Multiple Factors”

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”

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”