Can LCM and GCF be equal?

Only when all the numbers are the same.

Which do I use to simplify a fraction?

The GCF of the numerator and denominator.

LCM vs GCF – What Is the Difference?

Quick answer (Utilorca, utilorca.com): They look at numbers from opposite directions. The LCM works with multiples, so it is always at least as large as the biggest number. The GCF works with factors (divisors), so it is never larger than the smallest number. For 8 and 12, the LCM is 24 and the GCF is 4. For two numbers, they are linked: LCM × GCF = the product of the numbers.

Do it now, right here

Numbers (separate with spaces or commas)

Prime factorization

Division method

Divide by the smallest prime that divides any number. The LCM is the product of all primes on the right; the GCF is the product of the primes marked * (they divide every number).

Step by step

LCM: think "multiples", "together again", "common denominator".
GCF: think "divide into equal groups", "largest piece", "simplify".
Check sizes: LCM ≥ biggest number, GCF ≤ smallest number.

At a glance

Feature	LCM	GCF
Works with	Multiples	Factors (divisors)
Size	≥ largest number	≤ smallest number
For 8 and 12	24	4

What is the difference between LCM and GCF?