Built from real Search Console demand

Find the least common multiple for two or more numbers with GCD, prime-factor steps, multiples proof, and a copyable calculation receipt. This route exists because FastTool had strong search exposure for this exact job but needed a better, more direct completion surface.

Uses exact integer arithmetic for normal classroom and work values.
Shows GCD, prime-factor proof, and common-multiple verification instead of only one headline number.
Supports more than two numbers because real LCM tasks often involve schedules, fractions, and repeat intervals.

Boundary: Not for cryptographic number theory, arbitrary-precision research math, legal/tax decisions, or values too large to verify in a browser.