Yes
Yes, you do.
You DO need a common denominator to add, subtract, or compare fractions. You DO NOT need a common denominator to multiply or divide fractions.
Because it tells you how much the fraction is out of.
Unless you are using a calculator that adds them for you, it is much harder to add fractions with uncommon denominators. Having the same denominator allows you to only have to add the numerators for your answer.
They need a common denominator when you add them. For example, if you want to add 1/2 and 1/3, you need to change the fractions to equivalents that share the same denominator, so you can combine them. 1/2 + 1/3 = 3/6 + 2/6 = 5/6
To get the right answer when you add or subtract unlike fractions.
Because the answers will be wrong when adding or subtracting them if they don't have a common denominator.
Common Denominator means that the denominators in two (or more) fractions are common, or the same. The common denominator is important because before you can add or subtract fractions, the fractions need to have a common denominator.Sometimes fractions have different denominators, like 2/3 and 3/4. If you want to add or subtract them, they need to have the same denominator. In order to do that, you find a common denominator which is the same thing as a common multiple, only with denominators.
The denominators must be the same before you can add or subtract fractions.
No.
You add the numerators and put over the denominator.
because it would be diffcult to understand.[you don't add or subtract the demonters]