Number Bracelets

I went to Ruth Parker's session at CMC North 2015 and loved it. Of the many things I learned, I am perhaps most excited about Number Bracelets.

Here's how they work:

• Start with any two single digits. Say, 3 and 6. So the start of your bracelet is 6,3
• Add them together. You get 9. Now your bracelet looks like 6,3,9
• Add the last two digits in the bracelet. When you get a double-digit number, you only write down the 1's digit. So now our number bracelet looks like 3,6,9,2 (because 3+9=12, and 2 is the 1's digit)
• Keep going until it starts to repeat: 6,3,9,2,1,3,4,7,1,8,9,7,6,3,9 --> notice that it starts to repeat here. 
• The length of your number bracelet is the number of digits/terms before it starts to repeat. So in this example, the number bracelet starting 6,3 has a length of 12

I have so many questions I want to answer about these!!!

Bongard Problems

https://en.wikipedia.org/wiki/Bongard_problem
http://www.foundalis.com/res/bps/bpidx.htm

So awesome for understanding what a property is.

It would be interesting to do these with numbers in addition to diagrams.

Thanks, CMC North 2015!