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Introduction to Number Theory
Prime Peaks

Discover structure in divisibility, primes, representations and remainders.
Preparation: Integer arithmetic, prime factorization and fractions.
Current coverage: 12 core stages from Euclid’s algorithm through congruences and coprime counting.
4Topic levels
12Knowledge stages
528Practice problems
1LEVEL 1 · DIFFICULTY 1/5 within this course
Divisibility and Prime Structure
Organize factors and divisors.
Explore 3 knowledge islands
3 stages · 24 library problems · 108 checked variations · 2 × 6 assessment questions
Read the lessons →2LEVEL 2 · DIFFICULTY 2/5 within this course
Factorials and Representations
Understand place value and repeated factors.
Explore 3 knowledge islands
3 stages · 24 library problems · 108 checked variations · 2 × 6 assessment questions
Read the lessons →3LEVEL 3 · DIFFICULTY 3/5 within this course
Congruences
Solve problems using remainders.
Explore 3 knowledge islands
3 stages · 24 library problems · 108 checked variations · 2 × 6 assessment questions
Read the lessons →4LEVEL 4 · DIFFICULTY 4/5 within this course
Integer Equations and Counts
Combine integer constraints with exact counting.
Explore 3 knowledge islands
3 stages · 24 library problems · 108 checked variations · 2 × 6 assessment questions
Read the lessons → Progress earned through practice
Clear a stage by independently solving two different routine problems and one application in a new context. Hints help you learn; hinted answers and repeated solves do not count toward that target. Clear every stage to clear a level.
Every stage includes an explanation, two worked examples and eight library practice problems, plus checked variations with changing numbers and applications. Each level also has a separate unit test and a later review form. Parents see actual attempts, hint use and results.
These are independently authored core-skills courses, with the current scope listed for each course. They do not reproduce complete textbook contents. Difficulty describes the teaching sequence within each course; course preparation matters when comparing subjects. This site is not affiliated with or endorsed by AoPS. Results reflect these exercises and are not standardized scores. Content release math-courses-2026.09.08-v4.