The first five multiples for the numbers 4 and 6 are shown below.

Multiples of 4: 4, 8, 12, 16, 20, . . .
Multiples of 6: 6, 12, 18, 24, 30, . . .

What is the least common multiple of 4 and 6?
2
4
12
24

1 answer

To find the least common multiple (LCM) of 4 and 6, we can list the first few multiples of each number, or use the prime factorization method.

Method 1: Listing Multiples

  • Multiples of 4: 4, 8, 12, 16, 20, ...
  • Multiples of 6: 6, 12, 18, 24, 30, ...

From the lists, the smallest common multiple is 12.

Method 2: Prime Factorization

  • The prime factorization of 4 is \(2^2\).
  • The prime factorization of 6 is \(2^1 \times 3^1\).

To find the LCM, take the highest power of each prime factor:

  • For the prime number 2, the highest power from both factorizations is \(2^2\).
  • For the prime number 3, the highest power is \(3^1\).

Now multiply the highest powers together: \[ LCM = 2^2 \times 3^1 = 4 \times 3 = 12 \]

Conclusion

The least common multiple of 4 and 6 is 12.