Question

how would you get a common denominator for 12 and 16 for a subtracting probleme

Answer 1

multiply them together is the simplest solution:

(16)(12) = 112 + 60 + 20 = 192

Another way is to find the smallest number that both 16 and 12 are a factor of. Start by going thru the multiples of 12 and see which one 16 has in common:

1(12) = 12 1(16) = 16
2(12) = 24 2(16)=32
3(12) = 36 3(16) = 48
4(12) = 48

We see that "48" is the smallest number that they have in common; so we can use it as a common denominator