최대공약수 및 최소공배수 계산기

16과 24의 최대공약수는 8입니다. 이 계산기는 둘 이상의 자연수의 최대공약수와 최소공배수를 소인수분해와 함께 구합니다.

2~20개의 양의 정수, 쉼표나 공백으로 구분

결과

값을 입력하고 계산을 누르면 결과가 표시됩니다.

공식

gcd⁡(a,b)×lcm⁡(a,b)=a×b\gcd(a, b) \times \operatorname{lcm}(a, b) = a \times b

For two numbers, the GCD and LCM multiply to the product of the numbers.

이 계산기 사용법

  1. Type the numbers, e.g. 12, 18, 30.
  2. Press Calculate to see the GCD, the LCM and each number’s prime factorisation.

풀이 예제

GCD and LCM of 12 and 18

12 = 2² × 3 and 18 = 2 × 3².

GCD takes the lowest powers: 2 × 3 = 6. LCM takes the highest: 2² × 3² = 36.

The GCF of 16 and 24

16 = 2⁴ and 24 = 2³ × 3. The greatest common factor takes the shared primes at their lowest power: 2³ = 8.

The LCM takes every prime at its highest power: 2⁴ × 3 = 48.

Check: 8 × 48 = 384 = 16 × 24.

The GCF of 16 and 36

16 = 2⁴ and 36 = 2² × 3². The only shared prime is 2, at power 2: GCF = 4.

LCM = 2⁴ × 3² = 144. Check: 4 × 144 = 576 = 16 × 36.

자주 하는 실수

  • Mixing up GCF and LCM: the GCF is never bigger than the smallest number; the LCM is never smaller than the largest.
  • Using the highest power for the GCF: for 16 = 2⁴ and 24 = 2³ × 3 the GCF uses 2³, not 2⁴.
  • Stopping at a common factor that isn’t the greatest: 4 divides 16 and 24, but 8 is bigger.

자주 묻는 질문

What is the GCF of 9 and 36?

9, because 9 divides 36 exactly (36 = 4 × 9). When one number divides the other, it is the GCF.

Are GCF, GCD and HCF the same?

Yes — greatest common factor (GCF), greatest common divisor (GCD) and highest common factor (HCF, the usual UK name) all mean the same number.

Is GCD the same as HCF or GCF?

Yes. Greatest common divisor, highest common factor and greatest common factor all mean the same thing.

Where is the LCM used?

Adding fractions uses the LCM of the denominators — the least common denominator.

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