Surely you can calculate 54 to the 17th in your head, right?

German show features guy with astonishing ability to multiply in his head.

I think he moves his head back and forth while looking mostly ahead because he “sees” the calculations and numbers in his head. In a very minor way, by comparison, and nothing even remotely approaching his jaw-dropping skill, I “see” computer programming logic in my head when I’m writing code.