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# Video:How to Add Fractions

with Zoya Popova

Want to learn some great tips for adding fractions? It's easier than you may think.See Transcript

## Transcript:How to Add Fractions

Hi, I'm Zoya Popova for About.com, and today I'm going to show you how to add fractions.

### Basics for How to Add Fractions

When fractions have the same denominator, addition is easy. Just add up the nominators, and your denominator stays the same. So,1/5+2/5=(1+2)/5=3/5. But if you have to add fractions that have different denominators, such as 1/5+1/7, you first have to bring them to a common denominator. We take each of the fractions and multipy the top and the bottom by the same number. 1/5 multiplied by 7/7 is the same value as 1/5. And 1/7 multiplied by 5/5 is the same value as 1/7.

### More Basics for How to Add Fractions

When we perform these multiplications, you fractions now have common denominator, 35, so we can simply add the numerators:1/5+1/7=1/5*7/7+1/7*5/5=7/35+5/35=(7+5)/35=12/35.In this case, we acted intuitively. But for tougher cases, you should follow the step-by-step process of finding the least common denominator, or the LCD. Let's say the problem is 11/15+5/12. First, write down your denominators: 15 and 12.