[f_devd]

Depending on what you're trying to teach, I would think something like these would be nicer to read (but with minimal dependencies): https://github.com/jackkolb/TinyRSA or https://github.com/i404788/tiny-rsa

[jcalvinowens]

The point for me is a naive BIGNUM library that somebody who has only had high school level math can easily understand.