I think you are on to something there. Personally, I just don't see the advantage of using iSeven over iSix, though. I might start using iEight whenever they finally iron the kinks out of that one.
Explanation: the percent is modulus. Basically it's just divide the first number by the second and return the remainder. If you do number % 2, it will return 1 if it is odd and 0 if it is even.
For example 4/2 has a remainder of 0 and therefore is even. 3/2 has a remainder of 1, and therefore is odd.
It's not obscure. This is the example, with syntactic differences, for this problem in almost every programming book I've read. He just didn't include newlines.