Slightly jaded, I've often wondered about the nature/nurture side of ability regarding maths.
My Ds's are 7 and 4. Ds2 is very, very bright and able at maths. Ds1 is, without a doubt, exceptional. Far beyond my ability when I was his age.
But I wonder just how inherent it is...I love maths, studied it into higher education and am generally mathematically minded. I've never pushed the dc but dh surprised me once when ds1 was about 3 (and had shocked his school with his ability) by saying something along the lines of 'no wonder he's good at maths, you're always doing it with him'.
I was genuinely
and replied I'd never 'done maths' with him, he was 3 fgs 
But then the 'maths' I was doing with him was just General play, and my own mathematical brain would subconsciously put a maths spin on it. And when I thought about it, dh was right...I had 'done' a lot of maths with ds1. From counting to measuring when cooking, doing more and less with blocks, biggest and smallest, playing shop and counting money and so on...right from when he was a few months old. So how 'inherent' is his ability and how much because he was immersed in a maths 'environment' since birth?
Anyway, there's my brain fart of the day.