Say there's 2/3 and 1/2, it's called Least Common Denominator, so you need to look at the denominators which are 3 and 2.
Now list the multiples:
3: 1, 3, 6...
2: 1, 2, 4, 6...
As you can see both of them go into 6 the least amount of times because it's the one that they both can multiply.
Least Common Denominator - pay attention to the lower number in the fraction, if the number on the top of the fraction can divide the lower number (evenly) than you have not reached the LCD.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two things to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.
You need at least two numbers to find something in common.