have a head for (something)
1. To have the mental ability to do something well. I've always been good at math—I guess I just have a head for numbers.
2. To have the ability to withstand or endure something. I never had a head for flying before, but I'm getting used to it now that I have to travel so much for work.
have a head for figures
To have an exceptional mental ability to calculate numbers; to be good with numbers. I've always been good at math—I guess I just have a head for figures.