The Difficult:
I think the most difficult part of these sections for me will be doing the Extended Euclidean Algorithm. The instructions were hard for me to understand and I'm not sure that I would be able to do one. The rules for dividing in modular arithmetic didn't have a very long explanation, but I think I would be fine if I saw one demonstrated.
The Interesting:
I have never worked with modular fractions before and they looked interesting to me. I'm excited to try using them because they look like they make modular arithmetic with w.