You need to know the least common denominator (LCD) of 8 and 9 if you want to add or subtract two fractions with 8 and 9 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 8 and 9 is 72.
Here is a math problem example where you need to know the LCD of 8 and 9 to solve:
3/8 + 2/9 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
72/8 = 9
72/9 = 8
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 9 = 27
2 x 8 = 16
Step 3) Put it all together to solve the problem:
27/72 + 16/72 = 43/72
= 3/8 + 2/9 = 43/72
It's that easy! Once again, the lowest common denominator (LCD) of 8 and 9 is as follows:
72
Find Least Common Denominators
Enter another two numbers below to find the Least Common Denominator.