What goes into 12 and 30?

The numbers that go into both 12 and 30 are their common divisors. The divisors of 12 are 1, 2, 3, 4, 6, and 12, while the divisors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30. The common divisors of 12 and 30 are therefore 1, 2, 3, and 6. The greatest common divisor (GCD) is 6.