The least common multiple (LCM) is the smallest number that two or more numbers can be divided into evenly. In other words, it's the smallest number that all of the numbers have as a multiple.
To find the LCM of two or more numbers, we can start by listing the multiples of each number until we find the smallest multiple that appears in all the lists. A multiple is a number that you get by multiplying a number by another whole number.
For example, let's say we want to find the LCM of 4 and 6.
The multiples of 4 are: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40... The multiples of 6 are: 6, 12, 18, 24, 30, 36, 42, 48...
We can see that the smallest number that appears in both lists is 12, so the LCM of 4 and 6 is 12.
We use the LCM to add or subtract fractions with different denominators. When we add or subtract fractions with different denominators, we need to find a common denominator, which is the same as the LCM of the denominators. This allows us to add or subtract the fractions more easily.
So, that's the basic idea of the least common multiple. It's the smallest number that two or more numbers can be divided into evenly, and we use it to add or subtract fractions with different denominators.