# A Circle Circle

Happy 2015! This was our daughter’s first circle of the year, and our son’s first circle ever.  We now do 2 circles each week, at the same time.  We alternate leading each circle.  To keep the kids focused, we moved the big kids circle upstairs. Oddly enough, the only room with enough space is our master bathroom.  We bought a folding picnic table and benches, and it worked out really well, despite being slightly strange.

The Bathroom Picnic Table

## The Activities

1. Topics: Numbers, Primes: Book:  The Number Devil by Hans Magnus Enzensberger.  We read most of chapter three.

2. Topic: Venn Diagrams:  First I made a Venn diagram with necklaces as the objects, some with emeralds, some with rubies, some with both, some with neither.  I asked them questions such as “How many necklaces do not have rubies?”  Next, I had them draw an abstract version with one number per region (i.e., a region is labeled “4” if it contains 4 necklaces).  Finally, I gave them an abstract diagram for a new problem: superheroes who could fly, had super strength, both, or neither.  I gave each kid a sheet with a bunch of small Venn diagrams, and then when I asked a question, they had to fill in the appropriate regions which contribute to that answer.  For example, “How many heroes are super strong?” means filling in the two regions inside the “Strong” circle.  Materials available here.

3. Topics: Geometry, Geometrical Drawing, Angles:  We supplied one geometry kit per kid, which contains a small ruler, 90-45-45 triangle, 90-60-30 triangle, protractor, and compass.  I explained that you could use a ruler for measuring distances; drawing lines of a certain length; and connected two points.  Each kid made a constellation by connecting random points.  Next, we traced the 90-45-45 triangle and measured the angles using the protractor.  Finally, we practiced drawing circles with the compass.

## How Did It Go?

We had four kids this week.

#### The Number Devil

This chapter was a bit harder than the previous ones, because it talked about division and only one of the kids was able to readily do simple divisions (she knew 17 / 2 = 8 ½).  There was an interesting discussion of why you can’t divide by 0, but it was kind of tricky — I think the kids might have been able to understand it if we spent a whole activity on it, but they didn’t get it in passing.  Then there was the prime number sieve.  One of the kids pointed out you could cross out all the evens for 2.  I think a couple of the kids were a bit bored during the division part but they were all paying attention for the sieve (which also had some nice charts).  Everyone wanted to finish the chapter but we needed to move on.

#### Venn Diagrams

After I showed them the necklaces picture, I asked what kind of chart it was, no one remembered, but when I said “Venn diagram” someone said “Oh yeah”.  I asked them a bunch of questions such as “How many necklaces have emeralds?”  “How many have emeralds or rubies?”  They did quite well with only a couple issues.  They even were able to do “How many have either both rubies or emeralds or neither?”  The kids got the idea of coloring the small diagrams pretty quickly, and we did a bunch, going both ways (I say something, they figure out the regions; I color some regions, they tell me what it means).  One of the kids got behind because she was coloring so carefully (she colored the picture above).

#### Geometry Kits

Using a ruler to connect two points was new to them, so we did the constellation activity to practice.  At first, they were inclined to connect the dots freehand.  When I showed them the 90-45-45 triangle, I asked if anyone knew what a right angle was, and one kid said yes and made a big L shape with her arms (one straight up, one out to the left).  Measuring with a protractor was kind of hard to grasp, I think a couple of kids kind of got it but I’m not sure about the others.  As expected, it was fairly hard for them to draw perfect circles using the compass, but they were very impressed by my circles.  One kid really liked the compass and didn’t want to stop.