Table of contents

  1. Course Info
  2. Realistic Prerequisites
  3. Subject Matter
  4. Course Staff
  5. Lectures
  6. Problem Sets
  7. Exams
  8. Resources
  9. Grading
  10. Advice to Future Students
  11. Syllabus

Course Info

Class Size 118
Hours/Week 11.0 (61 responses)
Instructors Bjorn Poonen (Lecturer), Merrick H. Cai (UA)
# of Responses to Course 18 Underground Questions 23/118

Realistic Prerequisites

  • Proof experience and mathematical maturity are extremely important. This is where the 18.100B soft prereq is most useful.
  • It is helpful to have some background in linear algebra (18.06 material).

Subject Matter

  • Students thought the content was very cool.
  • Course content was very theoretical and abstract, covering fundamentals of algebra and going deep into proofs.
  • Students wanted more applications out of the class.

Course Staff

  • Course staff was very approachable, understanding, and helpful.
  • Professor Poonen and the TA’s showed legitimate interest in student’s questions.


  • The subject lectures covered all learning objectives.
  • Many students, however, felt discomfort asking questions live during lectures.
  • The pace of the class was marked in between “just right” and “too fast”.

Problem Sets

  • Many were content with the problem set and the rigor of it.
  • Many felt comfortable asking questions on the problem set to the TAs.
  • Students generally found the psets fun, challenging, and interesting.
  • Many found collaboration absolutely necessary.


  • Instead of exams, there were weekly open-book/open-Google quizzes. Many students found this format less stressful than traditional exams.
  • The quizzes were fair and covered the materials learned in class.



  • Grading was fair and transparent, and some even thought it was pretty generous.
  • 85% of the grade was from psets, and 15% was from the quizzes.
  • 90% guaranteed an A- or above, 80% a B-, 70% a C-.

Advice to Future Students

  1. “textbook, pretty spicy”
  2. “proofs. HAVE A PSET PARTNER
  3. Read the textbook, for sure. Also, watching the first couple of lectures during Summer before the course is super helpful since this class goes quite fast (coming from someone who has some proof experience, but did not take 100A/100B).”
  4. “Work on psets with other students, absolutely. It’s easy to make false assumptions or errors in logical reasoning, and discussing the material of the pset (not just the questions themselves, but even facts that are ‘unrelated’ to the questions) with others can illuminate lots of these mental lapses.”


Click here for a PDF of this course’s syllabus.