I remember as a kid (25+ years ago) I had a couple of these calculator type math learning gadgets. One was called Quiz Kid and the other was called Mr. Professor....or L'il Professor or something like that. I thought the Quiz Kid one was the better unit, but the L'il Professor one was more popular. The Quiz Kid used to eat batteries quickly too.
I rem in early grade-school, I was fascinated when we learned long division. I'd actually go home and make up my own problems to figure out.
These kinds of programs on the DS though.....they're probably the most dreaded carts a kid can receive. You know, they ask for Phantasy Star Zero or something similar and get an educational game instead. Gah!