“Reversed” Ages

A simple situation with a mother and daughter’s ages leads to many questions and interesting observations.

In August, at a summer board meeting of the Adult Numeracy Network, the fabulous Sarah Lonberg-Lew (@MathSarahLL) shared a problem. Well, it wasn’t really a problem, more like something she noticed. In the meeting, she asked what we noticed and what questions we might ask.

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Penny Collection

Solange led us in a meeting about teaching mathematics with a focus on discovery, investigation, and student thinking.

In this meeting, Solange presented us with the following problem:

Consider a collection of pennies with the following constraints:

When the pennies are put in groups of 2 there is one penny left over. When they are put in groups of three, five and six there is also one penny left over. But when they are put in groups of seven there are no pennies left over. How many pennies could there be?

Thank you to YouCubed.org for the problem.

Can you help us out? Can you find a solution? Can you find more than one? What strategies are you using?

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Civic Statistics and Statistical Literacy

Usha and Iddo led us through an approach to exploring statistics.

A number of us were part of a lovely meeting a while back on statistics. Iddo Gal started the meeting by sharing an overview of a guide he and a few colleagues created for teaching civic statistics and statistical literacy. Iddo is presented at the U.S. Conference on Teaching Statistics in Pennsylvania a few weeks after the CAMI meeting.

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The Secretary Problem

Audrey introduced the group to a classic problem from optimal stopping theory (whatever that is). 🙂

If you’re on the search for a new secretary, how would you choose who to hire? For June’s evening CAMI meeting, Audrey shared a classic problem with the group:

The Popular Secretarial Problem!

There are N applicants for a secretarial position. The applicants are interviewed in random order, and you must accept or reject a candidate immediately after interviewing them.

After you reject someone, there is no way to bring them back.

There is only one position available. So as soon as you accept a candidate, you’re done. What strategy should you use in order to maximize the likelihood of hiring the best candidate out of the N applicants?

Some of the assumptions we used when exploring the problem:

  • There is one best candidate.
  • If you could see all the candidates at one (you can’t), you would be able to rank them all from best to worst.
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Pentominoes!

We moved shapes around a 100-grid to find patterns that lead to algebraic generalizations.

Today’s problem was from this year’s annual meeting of the Adult Numeracy Network (ANN) at the COABE conference in New Orleans. Christin Smith, Patricia Helmuth, and Heidi Schuler-Jones led the group through a series of activities over the course of the day. The theme of the ANN annual meeting was the idea of revealing algebra in basic mathematics. In our CAMI meeting, we explored an activity that starts with adding on a 100-grid and finding patterns and then moves towards generalization.

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Return to the Fold

Usha and Sophie led a frenzy of folding, observing, counting, and predicting at Fashion Industries High School.

Update: Check out these related videos —> Numberphile | Doodling in Math Class | Wrong Turn on the Dragon

It was a beautiful spring day when Usha and Sophie represented CAMI at the 40th anniversary of the New York City Adult Basic Education Conference. Sophie gave a little history of CAMI…

  • CAMI was founded in November 2014
  • There have been 61 CAMI meetings
  • 104 teachers have attended at least 1 meeting
  • 15 different teachers have run a meeting
  • Average attendance at a meeting is 7.8 teachers
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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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Temperature is Cool

How do the functions for converting between Celsius and Fahrenheit work? Temperature talk during the coldest week of 2019 thus far.

At our evening CAMI meeting earlier this month, Kevin Winkler from CUNY Start led us in an exploration of the conversion between Celsius and Fahrenheit based on something strange he noticed while crossing the Brooklyn Bridge.

I wanted to bring that idea to the afternoon CAMI meeting, and also try to scaffold the exploration a bit, so that we could extend the invitation to our students. It also just happened to be the week where the Midwest was experiencing such cold weather that friends in Minnesota kept making the same joke over and over again about the temperatures there being colder than they were in Antarctica.

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