## Friday, November 8, 2013

### Lesson 5 - Year 2

 Move three matchsticks to make 5 triangles

Warm up:

This was a good warm-up even though it’s pretty easy (all you need to do is move either the left or right triangle to the top (so that two of its vertices would be touching the two other triangles’ vertices). I set up a couple of these so that the kids could work in pairs. Then, I had a pair come up and explain what they did. At some point, the kids had the right solution, but they didn’t understand that it was the right solution because they thought they only made 4 triangles (they didn’t count the big one).

When I was walking to the Orange Village, I met 5 parents. Each parent had three children. Each child had a friend with them. What was the minimum number of people walking to Orange Village?
After a bit of thinking and discussing, they realized that the “I” could’ve been the only one walking there (since everyone else could be walking the other way)
1)
Pretend that a policeman came and told you that someone stole a gold chain from a museum. Facts:

- There are only three people who could’ve done it- Max, Dima, and Sasha (they could’ve done it together with one of the other suspects but those are the only people that could’ve done it)

- Max never does anything bad without Dima

- Sasha can’t drive (let’s say they got there by car)
Was Dima involved?

Thinking…discussing…arguing… After a couple of minutes, they thought of some possibilities of what could’ve happened;
1)      If Max did it, then Dima did it also – in that case, Dima did it
2)      If Sasha did it, then someone would have to be with him because he can’t drive, so it could either be Max (who would be with Dima) or only Dima, which, in both cases, involves Dima
OR…
3)      Dima did it alone, in which case, well… Dima did it.
Deep thinking… “These seem to be no other options except the ones we thought of, and in all the ones we thought of, Dima was involved…” Suddenly the kids’ faces brighten up “Now the policeman knows who to arrest! Ha!”

Play mancala with paper plates and poker chips (that way it is more “hands on” because it bigger than the usual mancala game board)
Very fun, and it involves math and strategy. We slip up into teams- two kids with me, three kids against us. The kids took turns moving, and we played a couple rounds, and mixed up the teams (the kids liked it, but they soon got tired of it).

Make a rectangle out of these pieces (solutions are included in white/gray):

They played around with these for a little while, and solved it, afterwards announcing that since they solved it one way already there was no point in continuing (oh well.)