Phillip K. Trocki

My son worked his way through part of this book before I decided that it's just too easy for him. So, I'm not making him work through the rest of it. I have a feeling Book 2 (which I bought at the same time I bought this one) is also going to prove to be too easy. But, we'll have a look at it anyway. Still, it's a good program, I think, for kids at this level.