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Intermediate Number Theory

Number theory using algebraic techniques, multiplicative functions, Diophantine equations, modular arithmetic, Fermat's/Euler's Theorem, primitive roots, and quadratic residues. Much of the first half of the class emphasizes using the basic tools of the Introduction class in clever ways to solve difficult problems. In the second half, more theory will be developed, leading students to the beginning Olympiad level.

12 weeks

Diagnostics

ARE YOU READY? DO YOU NEED THIS?

Documents

SYLLABUS
12 weeks ARE YOU READY? DO YOU NEED THIS? SYLLABUS  

Schedule

Friday
Sep 20 - Dec 13
7:30 - 9:00
PM ET
Sep 20 - Dec 13
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$400 (~$34/lesson)
$400 (~$34/lesson)
CLOSED
Thursday
Feb 20 - May 8
7:30 - 9:00
PM ET
Feb 20 - May 8
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$400 (~$34/lesson)
$400 (~$34/lesson)
ENROLL
Friday
Apr 11 - Jun 27
7:30 - 9:00
PM ET
Apr 11 - Jun 27
7:30 - 9:00 PM Eastern
6:30 - 8:00 PM Central
5:30 - 7:00 PM Mountain
4:30 - 6:00 PM Pacific
Click here to see more time zones
$400 (~$34/lesson)
$400 (~$34/lesson)
ENROLL

AoPS Holidays

There are no classes November 25 ‐ December 1, December 21 ‐ January 3, May 24 ‐ 26, July 4 ‐ 6, August 29 ‐ September 1, and October 31, 2025.

Who Should Take?

Students should have a complete understanding of modular arithmetic, and a mastery of algebra through our Intermediate Algebra class (or a typical honors Algebra 2 class and some Precalculus) before taking this class.

Lessons

1 Introduction
2 Bases
3 Divisibility
4 Divisors and Multiplicative Functions
5 Prime Factorizations
6 Algebra in Modular Arithmetic
7 Linear Diophantine Equations
8 Perfect Squares
9 Fermat's Little Theorem and Euler's Theorem
10 Orders and Primitive Roots
11 Quadratic Residues and Squares
12 Sums of Two Squares

I enjoyed Intermediate Number Theory very much and I learned very many new things in it. Most of the topics in the second half of the class were new to me (e.g. orders, primitive roots, Pell equation, etc.) It was also valuable to have my proofs graded by an outside source, rather than by myself as when I just used AoPS books by themselves. The classes were very interesting and informative.