Don't they still post all the pictures of the presidents around the room in the schools?  They did when I was a kid.  Anyway, at 4th grade, a kid has seen and heard the list, from Washington on.  So, it's a bouncy or else the little twerp is as dumb as a box of rocks.  
The OP says he's a "stay at home dad."  He ought to have time to hit the books with his little darling, then.