Attendance: Bel (7), Tuh (7), Nia (4), and Bab (4)

We did two activities. The first one aimed at the level of the preschoolers and the second one for the 7-year old kids.

### Sorting with intersection (part 3).

```I gave them 5 images (boat, train, airplane, crow, butterfly) and put two separate loops of yarn on the table. I asked them to sort the pictures into modes of transportation and things that can fly.

We did 6 sets in total. The last one had a bed, a drum, a violin, a piano, and a dresser.

Source material comes from the excellent book Math from Three to Seven by Alexander Zvonkin. ```

They quickly put the plane, train, and boat together and the butterfly and crow. Bel then said the plane could also fly. She moved the loops of yarn so that they overlap and put the plane in the “intersection” (they didn’t know it was called an intersection until I told them). I later learned that Bel had seen intersecting sets at school so it explains why she moved the loops so quickly.

The preschooler mostly did what they did before: gathered the 3 objects with a similar trait then declared that the rest didn’t have that trait. I managed to direct them a little by grabbing the remaining two pictures and asking what the common feature was. After that, they created another set and found the object in the intersection.

The last set was interesting. I – or rather, Alexander Zvonkin – had planned the groups to be “furniture” and “music instruments” with the grand piano being both.

They put the music instruments together. Tuh said that the bed and dresser were “things you have in your room” then declared that you could also put the drum, violin, and piano (!) in your room so the kids put all those in the intersection. It was a good interpretation so I didn’t say anything more.

### Codes.

```For the next activity, I used pegboards and distributed a sheet with 6 codes like the one in the picture. I placed a peg in the middle of the top row and explained how the code works by doing the first few directions. This could be done on dotted paper or graph paper also.

They worked through a couple more codes. The idea and most of the codes for this activity come from Math Circles for Elementary School Students by Natasha Rozhkovskaya. I added one in honor of Valentine's day. ```

As the title of the book suggests, this activity was quite difficult for the preschoolers. I worked with Bab step by step. I think it was hard for them to remember where they were in the code. Also, they did not always pay attention to the number after the arrow. I worked with Bab. Nia could do most of the code above once she saw that it was a house from the older kids. Amazingly, the code at the end of the blog was easier for them. It was longer but the numbers were smaller.

A complication I did not anticipate was that the pegs were too big and the pictures were much clearer on paper. Bel and Tuh did half of Code 3 with pegs and could not figure out what it was. See the difference?

The seven-year old kids loved the activity. Maybe it is the excitement of discovering the picture? They kept working on more codes when the math club was over. I take it as a success.