I can't say enough about these books. We purchased them last week, and my son is obsessed with them! We bought the "Ask Me" Silver package. They facilitate discussion, education, and they are a such a fun way to discover just how their little mind is working!! They are pricey but after a few days I can say without a doubt they are worth their weight!! If you look up Egle Alisauskaite on Facebook, you can likely shoot her a message to have her come to your house. She is very nice, a genetics masters student from Lithuania here for the summer