Revisiting Grant Sanderson’s “fair division” video thanks to an Amy Hogan tweet

I saw a tweet from Amy Hogan this morning that reminded me of an old project:

Two thieves steal a necklace w/ 10 rubies and 14 emeralds, fixed in some arbitrary order on a loop of golden string. Show they can cut the necklace in 2 places so when each thief takes one of the resulting pieces, they get ½ the rubies and ½ the emeralds. From @MoMath1 #mathchat

— Amy Hogan (@alittlestats) June 6, 2021

The old project is here:

Grant Sanderson’s “Fair Division” video shows a great math project for kids

And Grant’s video is here:

Before we started the project today, I had my son watch Grant’s video. Here are some of his takeaways:

Now we tried to see if we could find a fair division of a string with two colors using only two cuts:

Finally, to wrap up we tried to see if we could do a fair division of a string with three colors using three cuts:

This is a fun and relatively easy project for kids, and also a way for them to see some really fascinating advanced math!