How to Calculate the LCM
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In mathematics, the Lowest Common Multiple (LCM) of two or more numbers is the smallest positive integer that is evenly divisible by each of the numbers. Calculating the LCM is important in various real-life applications such as finding a common denominator in adding or subtracting fractions, or scheduling events to happen at the same time. In this article, we will discuss different methods to calculate the LCM of two or more numbers.
1. Listing Multiples Method
This method involves listing the multiples of each number and then finding the least common multiple among them. Here’s how to do it:
a) List the first few multiples of each number.
b) Find the least multiple that appears in all lists.
Example: Finding LCM(4,5)
Multiples of 4: 4, 8, 12, 16, 20…
Multiples of 5: 5, 10, 15, 20…
The lowest common multiple of 4 and 5 is 20.
2. Prime Factorization Method
This method involves finding the prime factors of each number and then multiplying them together to get their LCM.
The process is as follows:
a) Find the prime factorization of each number.
b) List all unique prime factors.
c) Multiply the highest power of each unique factor.
Example: Finding LCM(8,12)
Prime factorization of 8: (2^3)
Prime factorization of 12: (2^2)*(3^1)
List of unique prime factors: {2, 3}
Highest power for each unique factor:
For 2: (2^3)
For 3: (3^1)
LCM(8,12) = (2^3)*(3^1) = 24
3. Division Method
The division method involves dividing the numbers by their common divisors until no further divisions can be made.
Here’s how to do it:
a) Find a common divisor of the given numbers.
b) Divide each number by the common divisor and write the quotients.
c) Repeat steps a) and b) until there are no more common divisors.
d) Multiply all divisors and quotients together to find the LCM.
Example: Finding LCM(8,12)
Dividing by 2:
8 ÷ 2 = 4
12 ÷ 2 = 6
Dividing by 2 again:
4 ÷ 2 = 2
6 ÷ 2 = 3
Dividing by 1:
2 ÷ 1 = 2
3 ÷ 1 = 3
LCM(8,12) = (2*2*1)*(2*3*1) = 24
These are just a few methods for calculating the Lowest Common Multiple (LCM). Choose whichever method you find easiest or most efficient for any given situation. Remember that practice is key when it comes to mastering mathematical skills!