## Wednesday, February 15, 2017

### 2/14 Valentine's Day Math Olympiad #4

By the luck of the draw (well really modular arithmetic), this year Valentine's day fell on a Math Club Tuesday. I don't really go in for holiday themed activities much but I was in the drugstore and in a fit of whimsy bought a bag of heart shaped gummies. So I ended up handing them out to the kids as they arrived yesterday which always makes the start of the session more exciting.  As I was going around the table, the thought crossed my mind "Gosh I hope they didn't eat a ton of candy already from their various class parties. If so some of the kids are going to bounce off the walls." That was fortunately not the case.

Thematically, I was in a bind again this week. We lost last week to the snow, next week is Winter Break and  I had to give another MOEMS Olympiad to stay on schedule. This made for a little too few free form sessions since the last one.  Looking forward, I'm going to try to fit in some kind of circle geometry oriented activity to build up to Pi Day. I have also been excited by some reading on function machines and am thinking if there is a fun game or activity inplicit in them.  That said, I appreciate the structure the MOEMS contest enforces. Done properly, this results in a lot of intense focus on the part of the kids on 5 problems over a half hour.   Providing this exposure to more challenging material is part of my over arching goals.

To start off the day, we went over the P.O.T.W (see: http://mymathclub.blogspot.com/2017/01/131-chessboard-problems-or.html)  The kids came up with two different approaches. The first leveraged guess and check and the fact that the overall perimeter was supplied to narrow down on the boxes dimensions. I wouldn't have thought to go this way, in fact I had considered removing the given perimeter since its not needed, but with it in hand this strategy works fairly efficiently.  The second was a more traditional completely Pythagorean Theorem based approach.

Moving on,  I proctored the MOEMS contest. Exponents reared there head again which seems to be a recurring theme for this year.  From what  I can tell so far, there was less conceptual issues with what does the notation mean.  But my work is not done.  Most kids given something like:

$$\sqrt{4^6}$$ will compute  $4^6$ first and then search for a root manually rather than notice that this is the same as $\sqrt{(4^3)^2}$ and thus the same as $4^3$. I'm hoping calling these problems out on the whiteboard afterwards will lead to growth over time.

On the positive side, I had one student who usually has not talked much this year raising his hand frequently and volunteering to demonstrate solutions during our followup whiteboard session. Noticing that trend was my favorite part of the day.

I went with 2 KenKen puzzles of differing degrees of difficulty for the kids to work on if they finished early.  These worked well, but I'll bring 3 next time since 1 student actually managed to finish them both before I was ready to move on.

P.O.T.W:

(This is a slightly modified version of a twitter problem I found from @five_triangles)

2/3 of the kids in one classroom exchanged cards with 3/5 of the kids in a second classroom. What fraction of the total kids didn’t participate?

#### Planning

I'm still brainstorming about next year.  I'm not sure if its going to be easier or harder to keep 6th-8th graders on task. One of my thought experiments, is whether I could present circle activities at different levels on different weeks and have the kids who found it either too hard or too easy due to the age gap work on practice MathCounts based activities.  Its also quite possible to use the pre-canned MathCounts curriculum which I'll definitely experiment with and see how I and the kids find it.

#### 1 comment:

1. The modified version is a big improvement on the original.