Chemistry

You know how when you are busy or immersed in some activity you start dreaming about it? Well, the other morning when Keith was getting up, I glanced at the clock and saw this:

I wasn't dreaming, but I read that as SO4 which is the chemical symbol for Sulfate. I am teaching Nathan and Lorissa chemistry, and I must have gotten too much of it the other day. They feel like any day with chemistry is too much!