You need to know the least common denominator (LCD) of 28 and 7 if you want to add or subtract two fractions with 28 and 7 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 28 and 7 is 28.
Here is a math problem example where you need to know the LCD of 28 and 7 to solve:
3/28 + 2/7 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
28/28 = 1
28/7 = 4
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 1 = 3
2 x 4 = 8
Step 3) Put it all together to solve the problem:
3/28 + 8/28 = 11/28
= 3/28 + 2/7 = 11/28
It's that easy! Once again, the lowest common denominator (LCD) of 28 and 7 is as follows:
28
Find Least Common Denominators
Enter another two numbers below to find the Least Common Denominator.