Great Mathematicians

Sofia Kovalevskaya was a great Russian Mathematician who claimed that she studied her father's calculus notes that were papered onto her nursery walls in place of wallpaper.  Maybe my kiddos won't become great writers, but in that same spirit, I have always kept the alphabet on their wall.  Today it got a facelift.  No worries, I realize the letter H is missing.  It takes quite a long time to finalize any projects at my house.  The great thing is, that while I'm concocting projects to benefit them, this was by far the more enjoyable activity for them: