X is a hard letter to find things to do with the kids, but they do know how to make an 'X and they use it. So, the first thing we talked about was xrays. I showed them some I had taken of my foot when I broke my toes. It is hard to know if they really understand all that, but we talked about it and they are now exposed to what an xray looks like.
Then I had cut out a big black x and they put white bones on them. Some of them colored the pages and the x's but they enjoyed it.