Combination locks use order, rotation, and wraparound numbers to turn a short code into a precise opening sequence.
Category - Number Theory
Math lessons about integers, divisibility, primes, remainders, modular arithmetic, and related number patterns.
Akshay Dinesh
How the Euclidean Algorithm Finds the Greatest Common Divisor
The Euclidean algorithm uses repeated remainders to find the greatest common divisor without listing every factor.
How Check Digits Catch Mistyped Numbers
Check digits use simple arithmetic to catch common typing mistakes in barcodes, ISBNs, card numbers, and other everyday identifiers.
How Prime Factorization Makes GCD and LCM Easier to See
Prime factorization turns GCD and LCM problems into a clear comparison of building blocks instead of guesswork with long lists.
How Modular Arithmetic Makes Remainders Useful
Modular arithmetic turns remainders into a useful system for clocks, calendars, codes, cycles, and number patterns.
