I absolutely suck at basic and mental math; but sit me down in front of a paper and a pen, and I'll give you answer to whatever calculus problem you'd like...

Provided it's not an obtusely difficult problem and I'm afforded the internet to get the necessary formulas and a refresher on how to use them, of course. And if not, I could always just go hunting for my cal1&2 notebooks to review

But if anyone wanted me to make a multiplication table relying solely on either mental math or from memory... I'd tell them to pound sand. I'd rather just use excel or something