Answer:
True
Step-by-step explanation:
You could use any common multiple, but using the least common multiple is easier and faster, which is why it is usually recommended. For example:
In order to add, you need to find the least common multiple, which would be 12. (and you can't forget, what you do to the bottom, you must do to the top as well)
However, this is only necessary with addition and subtraction, not multiplication or division.