Cotter Tens Fractal

Looks kind of like a Christmas tree...

This is something LMS and I did in math (we're using RightStart Math Level B), and is a great way to visualize numbers.

The huge triangle is made of 10 smaller triangles.

Those triangles are in turn made of 10 smaller triangles, and those triangles are also made of 10 smaller triangles.

Confused yet?

We glued 10 small triangles onto a medium triangle and repeated for a total of 100 medium triangles. The small triangles represent ones, so if there's 10 ones in a medium triangle, a medium triangle represents 10.

We then glued 10 medium triangles onto a large triangle and repeated for a total of 10 large triangles. Since there's 10 ones in a medium triangle and 10 medium triangles in a large triangle, a large triangle represents 100.

We then glued 10 large triangles onto a giant triangle. Since there's 10 of them and each one represents 100, the giant triangle represents 1000.

1000 small triangles = 100 medium triangles = 10 large triangles = 1 giant triangle

If I'd thought about it ahead of time, I'd have used a different paper for all the small triangles, which would have made it easier to see each individual triangle.

This took a lot of time and a lot of glue sticks, but was pretty interesting. I will admit that this is the first time I'd heard of a Cotter Tens Fractal (at least that I remember), so I'm already learning new things!

Have you heard of a Cotter Tens Fractal?