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##### Asked by: Constanti Gromba

business and finance interest rates# How do you solve the least common denominator?

Last Updated: 15th February, 2020

**Here are the steps to follow:**

- Find the
**Least Common Multiple**of the**denominators**(which is called the**Least CommonDenominator**). - Change each fraction (using equivalent fractions) to make their
**denominators**the same as the**least commondenominator**. - Then add (or subtract) the fractions, as we wish!

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Then, what is the easiest way to find the least common denominator?

To **find the least common denominator**, simply listthe multiples of each **denominator** (multiply by 2, 3, 4, etc.out to about 6 or seven usually works) then look for the**smallest** number that appears in each list. Example: Supposewe wanted to add 1/5 + 1/6 + 1/15. We would **find the leastcommon denominator** as follows…

One may also ask, how do you find the LCD of 2 fractions? When we add or subtract **fractions**, theirdenominators need to be same or common. If they are different, weneed to **find the LCD** (**least common denominator**) ofthe **fractions** before we add or subtract. To **find theLCD** of the **fractions**, we **find** the least commonmultiple (LCM) of their denominators.

Likewise, people ask, how do you find the LCD?

Divide the **LCD** by the originaldenominator. To **determine** the multiple needed to make thedenominators equal, divide the **LCD** you **determined** bythe original denominator. Multiply the numerator and thedenominator of each fraction by this number. The denominatorsshould now both be equal to the **LCD**.

How do you make denominators the same?

Adding and Subtraction Fractions Back to the first example: Once you find the **commondenominator**, you multiply the numerator of each fraction by the**same** number the **denominator** was multiplied by. Nowthat the fractions **have** the **same denominator**, you canadd them together.