Stage 37 · Beyond (Optional)

37.3.4 Congruence: Arithmetic on a Clock

37.3 First Steps in Number Theory: Divisibility, Congruence, and Primes

Point 4 of 5

37.3.4 Congruence: Arithmetic on a Clock

Core idea

Just as a clock loops back to 1 after 12, numbers sort into classes by their remainder mod m, and a ≡ b (mod m) means they're congruent.

Module goal. Starting from divisibility and remainders among the integers, meet the prime numbers as building blocks and congruence as a clock arithmetic, and feel the beauty of pure structure.

eastmath.com · 37.3 First Steps in Number Theory: Divisibility, Congruence, and Primes · 37.3.4 Congruence: Arithmetic on a Clock