Need Help?
Need help finding the right class? Have a question about how classes work?
Introduction to Number TheoryFundamental principles of number theory, including primes and composites, divisors and multiples, divisibility, remainders, modular arithmetic, and number bases. 
12 weeks 
12 weeks ARE YOU READY? DO YOU NEED THIS? SYLLABUS 
Schedule
Thursday
Sep 10  Dec 3 
7:30  9:00
PM ET
Sep 10  Dec 3
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 
Andrew Sayler 
$340
$391 w/books

$340
CLOSED
With Books $391

Friday
Sep 25  Dec 18 
7:30  9:00
PM ET
Sep 25  Dec 18
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 
Ahram Feigenbaum 
$340
$391 w/books

$340
FULL
With Books $391

Sunday
Dec 6  Mar 7 
7:30  9:00
PM ET
Dec 6  Mar 7
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 
Luís Finotti 
$340
$391 w/books

$340
ENROLL
With Books $391

Thursday
Dec 10  Mar 11 
7:30  9:00
PM ET
Dec 10  Mar 11
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 
Adam Rumpf 
$340
$391 w/books

$340
ENROLL
With Books $391

Spring 2021  This course will be offered in Spring 2021. Click here to join our mailing list to be notified when the course schedule is available. 
AoPS Holidays
There are no classes October 31, November 23–29, and December 21–January 3.
Who Should Take?
This course is appropriate for students in grades 69 who have mastered basic algebra up through solving linear equations and manipulating multivariable expressions. Students who have completed our Introduction to Algebra A course should have sufficient background. Students who are already proficient with modular arithmetic and basic Diophantine equations do not need this course. This course is roughly the same difficulty as our Introduction to Counting and Probability class. For those preparing for contests, this course should help with MATHCOUNTS and the AMC 8/10/12 tests.Lessons
Lesson 1  Integers, Fractions, Decimals, and Number Bases 
Lesson 2  Base Number Arithmetic 
Lesson 3  Multiples, Divisors, and Prime Numbers 
Lesson 4  Common Factors, Common Multiples, Euclidean Algorithm 
Lesson 5  Divisor Problems, More with the Euclidean Algorithm 
Lesson 6  Factorials, Special Integers, Algebra with Integers 
Lesson 7  Units Digit, Introduction to Modular Arithmetic 
Lesson 8  Calculations with Modular Arithmetic 
Lesson 9  Divisibility Rules and Multiplicative Inverses 
Lesson 10  Multiplicative Inverses, Solving Linear Congruences 
Lesson 11  Systems of Linear Congruences and the Chinese Remainder Theorem 
Lesson 12  Number Sense and Applications of Number Theory 
Required Textbook
Introduction to Number Theory
A thorough introduction for students in grades 710 to topics in number theory such as primes & composites, multiples & divisors, prime factorization and its uses, base numbers, modular arithmetic, divisibility rules, linear congruences, how to develop number sense, and more.
