Greatest common divisors and least common multiples can be applied in more practical scenarios than you might expect: from buying sandwich ingredients efficiently to being able to create complex musical patterns by overlaying many different rhythms.
Expect to see and learn how to solve questions like this one:
Once you’ve mastered the techniques for studying the factors and multiples of numbers, a natural next step is to consider comparing two numbers by these measures: given any two numbers, what divisors do they share and what multiples do they share? The computation of the greatest common divisor and least common multiple are only the beginning; from there it’s possible to reach towards many more advanced proofs, techniques, and practical applications!