## Tuesday, July 11, 2017

### Factor Game

 Factor Game - Illuminations
During the 1980s I was creating math "apps" that I called Microworlds because they were written in the Microwords programming environments. Today some of these microworlds still exist using a different platform. In this blog I am featuring the Factor Game which you may be familiar with because of its availability in NCTM's Illuminations library. NCTM acknowledges Connected Math as the source for this game. I used the game in a similar framework as the lessons that Connected Math uses. They do a "3 Act" sequence popularized by Dan Meyer only they call it the "Launch-Explore-Summarize" sequence. In my teaching days I used the “Set the Stage-Do the activity-Debrief" strategy. Of course, Madeline Hunter set the stage for all of us "3 Act" fans with her very dated  "anticipatory set-instruction-independent practice" strategy - not anything I would recommend today. Here’s my Factor Game’s three part strategy.

Factor Game - The Launch (Setting the Stage)

Figure 1

How to play the game
This is  a large group activity. Split the class into two groups and assign a captain to each group. On the blackboard or white board tape sixteen 3 by 5 cards (or use post-its) numbered from 1 to 16. (See Figure 1.)
Figure 2 - Game board

The teams compete for the highest score by picking numbers from the game board (Figure 2).  For example, let’s say Player A chooses 15. That means that the 15 card gets moved to team A’s column and team A has 15 points. Meanwhile Team B is entitled to receive the factors of 15 (1, 3, and 5) for a total of 9 points. (See figure 3.)
Figure 3

Whether Team B gets the points or not depends on them knowing that they are entitled to getting those cards. The students have to tell you (the teacher) what to do. Here’s an example. Let’s say Team A goes first and after some discussion they decide to choose 15. The team captain will then announces their choice. You then move the 15 card to Team A's total. You then ask Team B if there are any cards on the board that they are entitled to. The team B captain would direct the teacher to move the 1, 3 and 5 to Team B's hopper for a total of 9 points. (See Figure 3.) If team B doesn’t know or makes a mistake it is the obligation of the other team to catch it. This keeps the students attentive and engaged. If some errors are not picked up by the students, the teacher should make sure they are aware of it. One problem might be that team B chooses a number that is not a factor of 15.  Team B would then lose their turn.  Play continues until all the remaining cards do not have a factor on the board. The game ends at that point. Team with the highest score wins.

Important note: Play one game as a practice learning game. In this way the students discover the rules for the game on there own. And that makes it more exciting for them.

Here’s a quick sample game (figure 4).

Figure 4

Though Team A went first they made a bad choice because they gave up 9 points. A better first choice would have been to take the largest prime number which was 13. Team B would have received only 1 point for a 12 point advantage. That's a very large disadvantage to overcome in a game consisting of only 16 numbers.

Explore (Do the activity)

Once the students get the hang of playing the 16 game with cards or post-its on the board, have the students open the Factor Game on their computers. Set the board to show numbers from 1 to 16. Have the students play several games against the computer. The challenge for the 16 game is to figure out if going first is always an advantage. In other words can they always beat the computer in the 16 game if they go first? Once they figure that out, have them play the 25 game. Does the team going first still have the advantage? Try the 30 game and see if going first continues to be a winning pattern or not.

Summarize (Debrief)

Question for students: What did we (including the teacher) learn from playing the Factor Game? Did you find that some numbers are better than others to pick for the first move?

Followup activity: Make a table of all possible first moves (from 1 to 30).

Figure 5

What is the best first move in a game of 30? Explain.

Extensions (for student projects):

The Factor Game applet was adapted with permission and guidance from "Prime Time: Factors and Multiples," Connected Mathematics Project, G. Lappan, J. Fey, W. Fitzgerald, S. Friel and E. Phillips, Dale Seymour Publications, (1996), pp. 1‐16. However the idea for the Factor Game was predated by Dr. Factor which originally appeared as one part of a four part program called Playing to Learn published by HRM and Taxman circa late 70s early 80s. David Bau writes about Taxman in his 2008 blogpost:
The Taxman game is (apparently) an old programming exercise. But it is also a good game for practicing factors [and problem solving]. […] Here is a gadget that applies the rules of the game for you. The board defaults to 100 numbers but you can start with 20 by changing the number next to Restart button. Can you beat the Taxman?
The Taxman metaphor is a good one because the factors can be thought of as the currency to be paid to the taxman. If no factors remain for the numbers that are left on the board, the taxman (greedily) gets the rest of the numbers and the game is over. It’s challenging to beat the Taxman, but if you keep trying there is a sequence to beat him in the 20 game. Try it for other numbers as well.

David Bau continues:
It is worth playing without reading anything else - it is not too hard to find a heuristic that beats the taxman. The game was written up in an article by Robert Moniot in the Feb 2007 MAA Horizons - an optimal strategy is not known. I've gotten up to 121 points on the 20-size board; I am pretty sure this is not optimal. Can you beat the board with say 30 squares? What is the best score you can get?
Robert Moniot shared a little history about the Taxman game:
After the Math Horizons paper appeared, I learned that the game (Taxman) was invented by Diane Resek of San Francisco State University. She writes: “I came up with the game when I was working at the Lawrence Hall of Science in Berkeley from about 1969 to 1972. I was coordinating a grant Leon Henkin (UC Berkeley) and Robert Davis (I think he was at U of Illinois at that time) had from NSF to work with K-6 teachers in the Berkeley Unified School District. One of the things I tried to do was to come up with interesting ways for kids to practice their skills or their facts which would involve them in some thinking and not be so boring. The Taxman was one game I came up with for multiplication facts. It was named for the Beatle's song -"Taxman". At the same time other people were working with kids on teletype machines. They taught them Basic and had games on it for them to play. When I came up with a game or an activity, they would turn it into a program. (slightly edited). (Source)

## Friday, April 28, 2017

### Look at me. I’m a teacher!

My first day in front of a room filled with kids scared the hell out of me, but I kept my confident veneer. As a first year teacher, I was assigned 5 classes – 3 Algebra 1 and and 2 General Math. When I asked for advice about teaching the general math classes I was told to give them busy work. The textbook we used was at least 10 years old, and there wasn’t much in it that my students could relate to. Sometimes I pretended to be doing something important at my desk so I would let them chat away the “study” period that I had given them.  Fortuntely, it never came back to haunt me, although I did feel guilty about it. What was the matter with me?  I wasn’t sure which was more boring  - teaching them or watching them learn. A couple of them reminded me of the girls who used to sit in the back of the room with the sweathogs in the Welcome Back, Kotter TV show.  Why was I so irresponsible? Because I really didn’t know what to do with them.  So I chickened out and hid behind busy work pretending it was important.

The Algebra classes, on the other hand, were fun for me. The students were motivated. About 35 years later I heard from a couple of them thanking me for making it interesting for them. (Thank you, Internet.) I appreciated it.  Better late than never.  I still plan to visit one of the students in California. OMG, he’s in his 50s.

The Stock Market Game

So three/fifths of my day was fine, but the other two/fifths of general math classes was boring for both my students and me.  I really didn’t know it, but we had an unspoken compromise, a kind of truce where we agreed that if they didn’t act out and looked busy, I wouldn’t bother them or try to make them think. They had collectively given up on math long before they even got to me.  I knew I wouldn’t be able to do this forever. I could stand it for just so long.  Something had to give.

Then I got a break. On one of my caffeine energized mornings in the spring of 1968, I  read about how the stock market was doing well, gaining momentum.  It seemed that any stocks in those early 60s carrying the name “tronics” became “highflyers.”  The electronics sector was responsible for a 2 year bull market after President Johnson’s state of the Union address on January 10, 1967.  Despite my math background the electronics field was virgin territory for me, as was the stock market  It wouldn’t be until 1970 that I’d  spend \$70 on my first Bowmar “brain” calculator.  I was intrigued by how the mainframe (whatever that was) seemed to be rocket propelling the stock market.

I was still thinking about the stock market when I discovered a Stock Market game in a department store. I thought it would interesting to try it with my general math classes. At this point, I had no real hope for anything. Nothing to lose.  I just wanted another way to get through the day.

Okay – despite how this sounds – like something scripted in a movie – It really did happen.   I bought the board game and we played it. It was a hit!  Even the principal stopped by my room to see what all the ruckus was about. He just stood there dumbfounded not sure what to make of it. The sweathogs were having fun doing something educational.  Kids engaged in buying and selling stocks. Now, fast forward 50 years and I’m playing the same game with a group of distracted 6th graders. But I’m getting ahead of myself. I’ll return to Stocks and Bonds in a later chapter.

We had fun and my students were doing math willingly because they wanted to not only win the game but doing math made sense to them. I had stumbled upon something so pedagogically important that I would never forget it: sustained willing engagement.*

* This is an excerpt from my book The Wannado Curriculum A Math Teacher's Journey to the Dynamic Math 2.0 Classroom available from Amazon.