Birthday Equation for Math Nerd Boyfriend

Tomorrow is my boyfriend’s birthday and he is a huge math nerd! He loves number theory, cryptography, and irrational numbers.

I would love to give him a fun equation or something interactive and mathematical included in the gifts I have for him. Something where he has to do some math and get some sort of message or something specifically for him. I found his birthday magic square, but I want more ideas.

Suggestions?

Author: MarketingScary5038