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##### Asked by: Constanti Gromba

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

**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!

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…

**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**.

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.