we love math

my eleven year old bro just walked into my room and looked at some flier which had the equation Y=Hx+Z on it. he asked me why this math was so cheem and when i told him it was what he was gonna do in future, he looked really perplexed.
so i guess he decided that he should start building up his foundation in algebra by asking me some qns.

bro: so jie, what's a+a

me: 2a. do you know what a X a is then?

bro: -blank look-

me: a-square

bro: orh... so a+a+a is 3a la!

me: yup. so what's aXaXa?

bro: -ponders for a moment-
(confidently) i know! a-triangle!

dots.