Before we reached that point, I took advantage of the recent largest prime number discovery and had a quick math chat about Mersenne primes and 274,207,281-1 More Info. Everyone seemed interested so I'm tempted to go with a prime number based activity next week. Also before I had the volunteer work on the white board I reminded everyone about working on listening to each other and made a few comments on how the problem had a lot of unconstrained parameters that seemed important but we wouldn't need to find in order to reach the solution.
Here' the original video: http://www.artofproblemsolving.com/videos/prealgebra/chapter15/311 which does a very entertaining job of explaining the solution.
At this point we were ready to go with the latest (and slightly delayed) Olympiad. I was tempted to hold it off another week but that risked bunching too many of them in February. Again we had seven new students. So this required discussing how the Olympiads work, the basic rules, and why we do them. Overall this year's procedure works much better than how I approached them my first year
1. I always remind everyone to read carefully / double check their work.
2. Check up front for kids missing pencils.
3. Bring a light activity for those who finish early so they are occupied and don't distract the test takers who are left. I also tend to move the early finishers to one corner of the room to further insulate them from those still working.
4. Always go over the problems right after finishing. (Don't wait a week) Kids really want know if they found the right answer. So they are super motivated to listen to each other show their solutions.
5. Always try the test out first yourself on the same day so you don't forget the problems. I tend to look at the problems more from the perspective now of what do I think will be harder for the kids to solve. If I have time, I'll even practice some explanations for areas that I think might be more difficult.
This set was about average in difficulty and based on a quick glance as kids handed them to me, I think everyone did really well this time. Interestingly, there was no regrouping or distributive law problem, the first time I've every seen that omission. Instead, the easiest problem was an odd take on Pythagorean triples that I found a bit flat. When we went over it, I actually asked if anyone recognized the numbers. I had one boy spot the 3-4-5 tuple which let me go off on a small riff on the subject and draw everyone's favorite picture:
I'll have to take a look at the scope and sequence for Fourth Grade again because I'm hoping we can do some geometric inquiries into the proof the of the theorem later on. I have least 2 ideas since last year on alternate approaches the kids could look into. This I will definitely want to coordinate so that everyone is at least familiar with the theorem.
The really neat part about the answer discussion was I was able to call on almost every single kid in the room, including all of the new students. So I think everyone has been up to the whiteboard and discussed their work at least once now.
For my filler activity for the early finishers I chose a followup congruent shape worksheet from Matt Enlow:
Just like last week, these worked really well drawing everyone in. And since we had about five minutes to spare at the back end of the hour, everyone had a chance to start working on it.
Finally: I went back to the UWaterloo site for the problem of the week:
I think this one will prove easier for everyone despite its classification.