Video Transcript
Find the LCD of the following pair of fractions: two-thirds and five-eighths.
The LCD is the lowest common denominator. We can find this by finding the lowest common multiple of the two denominators, in this case three and eight. The multiples of three are the numbers in the three times table, the first 10 of which are three, six, nine, 12, 15, 18, 21, 24, 27, and 30.
The multiples of eight are the numbers in the eight times table. These are eight ,16, 24, 32, 40, and so on. We’re looking for the lowest number that is a multiple of both three and eight. In this case, our answer is 24. Therefore, the lowest common denominator of two-thirds and five-eighths is 24.
You might notice at this point that three multiplied by eight is equal to 24. In fact, multiplying the two denominators will always give us a common denominator. However, it is important to note that this will not always be the lowest common denominator.
