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!!!

Dictionary of Numbers

A Chrome extension that gives context to numbers.

From playing around with it, it's not as easy as I'd like, but there are some cool things. Did you know that the International Space Station weights 1 million pounds? I like the idea of giving context to numbers so that kids/people can have a reference point, especially for big numbers.