You need to know the least common denominator (LCD) of 9 and 10 if you want to add or subtract two fractions with 9 and 10 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 9 and 10 is 90.
Here is a math problem example where you need to know the LCD of 9 and 10 to solve:
3/9 + 2/10 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
90/9 = 10
90/10 = 9
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 10 = 30
2 x 9 = 18
Step 3) Put it all together to solve the problem:
30/90 + 18/90 = 48/90
= 3/9 + 2/10 = 48/90
It's that easy! Once again, the lowest common denominator (LCD) of 9 and 10 is as follows:
90
Find Least Common Denominators
Enter another two numbers below to find the Least Common Denominator.