I went to Sigma
- Back when I went it was very cheap (like $60 for 2 hours, idk what it is now), assuming it went up due to very very high demand
- Notes were very in depth, I basically used the booklets as my notes for exams, didn't bother writing my own notes like I did for biology
- The questions in the booklets/in class worked through together, and included both standard questions and very tricky things they may ask so you're well prepared
- Had weekly homework that he would mark as well as practice/mock tests in class so that was helpful
- Tries to make funny jokes (good effort)