Read this article to figure out how to calculate the lowest common denominator of . Learn the two different methods that you can use to find the LCD: the prime factorization method and the LCD formula method. We will explain both these methods in detail so stick around until the very end to understand. Utilise our free LCD Calculator to avail the LCD of numbers easily.
Given numbers are 640,650,780
We can find the LCD of numbers 640,650,780 by the prime factorization method or by applying the LCD formula.
The LCD of 640,650,780 is 124800.
2 | 640, 650, 780 |
2 | 320, 325, 390 |
5 | 160, 325, 195 |
13 | 32, 65, 39 |
32, 5, 3 |
As you can see, now we have to multiply the prime numbers on the left side with the co-primes at the bottom.
2 x 2 x 5 x 13 x 32 x 5 x 3 = 124800
Thus, we have determined that the LCD of 640,650,780 is 124800
The LCD formula is LCD(a,b) = ( a x b) / GCF(a,b)
Step1:
Find the GCF of 640 and 650. To find the GCF, list down the factors of 640 and 650 and select the highest factor that appears in both lists of factors.
640 : [1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640]
650 : [1, 2, 5, 10, 13, 25, 26, 50, 65, 130, 325, 650]
From this, we can see that the GCF of 640 and 650 is 10.
Now, put this into the LCD formula.
LCD(640, 650) = ( 640 x 650 ) / 10
LCD(640, 650) = 416000 / 10
LCD(640, 650) = 41600
Step2:
Find the GCF of 41600 and 780. To find the GCF, list down the factors of 41600 and 780 and select the highest factor that appears in both lists of factors.
41600 : [1, 2, 4, 5, 8, 10, 13, 16, 20, 25, 26, 32, 40, 50, 52, 64, 65, 80, 100, 104, 128, 130, 160, 200, 208, 260, 320, 325, 400, 416, 520, 640, 650, 800, 832, 1040, 1300, 1600, 1664, 2080, 2600, 3200, 4160, 5200, 8320, 10400, 20800, 41600]
780 : [1, 2, 3, 4, 5, 6, 10, 12, 13, 15, 20, 26, 30, 39, 52, 60, 65, 78, 130, 156, 195, 260, 390, 780]
From this, we can see that the GCF of 41600 and 780 is 260.
Now, put this into the LCD formula.
LCD(41600, 780) = ( 41600 x 780 ) / 260
LCD(41600, 780) = 32448000 / 260
LCD(41600, 780) = 124800
LCD of 640,650,780 is 124800
Here are some samples of LCD of Numbers calculations.
1. What is the LCD of ?
Answer: LCD of is .
2. How to find LCD of using prime factorization ?
Answer: Just keep dividing by prime numbers until only co-primes are left over. At that point, simply multiply the co-primes with the prime numbers on the left. The answer will be , the LCD.
3. How to Find the LCD of using LCD formula ?
Answer: The LCD formula is LCD(a,b) = ( a x b) / GCF(a,b).
You must first calculate the LCD OF and . Then, find the LCD of that answer and and so on. The answer will be , which is the LCD of .