Maybe I'm weird, but I knew right away that 91 = 7 x 13. Apparently you felt the same way.

I actually figured 91 = 70 + 21 = 10 * 7 + 3 * 7

It's funny that I get upvoted for possessing 3rd grade arithmetic skills.

3rd grade in Bulgaria, maybe. To us Americans, that's like an amazing magic trick.

Definitely shouldn't have to resort to tricks to factor 91. The answer really jumps out (70 + 21).

Yes... no