"I'm concentrating on my numbers"

Avi has been very focused lately on figuring out addition facts. This morning he was talking about some of them at breakfast, 4+4=8 etc. Then I was trying to ask him a question about lunch or some other unimportant thing and he wasn't paying attention to me. Finally he said with a patient explanatory air, "I'm concentrating on my numbers.". Then he said to me, "3 plus 2 take away 1 is 4!"
For the record, we haven't done anything to promote this math obsession. We are just supporting his enthusiasm as it arrives.

Now, as I write this he is rolling around on his bedroom floor (NOT getting dressed for school like he's been asked multiple times) and singing "Oh Hanukkah" with a typical four-year-old attempt at the lyrics. Got the main idea, but throws in (or leaves out) some extra words.