What is LCM

LCM is the shorthand for Lowest Common Multiple (or Least Common Multiple). It is the smallest number that is a multiple of 2 or more numbers.

To work it out between two or more numbers, we work out the prime factorisation of the numbers and then use them create the LCM.

For example the LCM of 8 and 20:

We work out the prime factorisation for both.

8 = 2 x 2 x 2

20 = 2 x 2 x 5

We need the LCM to include both factorisations but be the smallest number to do so, so we need the LCM to contain 3 2s, and a 5.

LCM = 2 x 2 x 2 x 5 = 40

Least Common Multiple(LCM) is a method to find the smallest common multiple between any two or more numbers. A common multiple is a number which is a multiple of two or more numbers.

LCM is the the lowest common multiple of two numbers. It is the smallest positive number that is divisible by the two numbers

LCM is least common multiple .for example LCM of 5 and 15 is 15 . If you observe the common multiples of 5 and 15 , there are 15, 30 , 45 and so on

LCM stands for Least Common Multiple. It is basically used to find out all the least and common multiples between all the numbers given

LCM stands for Lowest Common Multiple.

To explain the words:

Lowest => Smallest

Common => To have something in 'common', the Multiple (see next) will apply to both or all of the numbers in question. The number we are trying to find will be in the times-tables of the numbers we are given.

Multiple => think 'multiplication', so the multiple will normally be a large number, greater than or equal to one of the numbers in question.

In the 2 examples below we will look at finding the LCM using lists of times-tables.

For more comples numbers, or trying to find the LCM of more than 2 numbers, finding the prime factors (a recap on prime factors would be ideal before using this method) would be more efficient.

Example 1:

Find the LCM of 4 and 12.

We want to find the smalllest number in the times-tables of 4 and 12.

There are several methods to find the LCM. If the numbers are small (1 or 2 digits), one option is to write out the times-tables of 4 and 12 and see which one is the first in both numbers:

4 times-tables: 4, 8, 12, 16, 20, . . .

12 times-tables: 12, 24, 36, 48, . . . .

Looking at the list of numbers, the first number in both times-tables is 12: 3x4 = 12 and 1x12 = 12.

So the LCM of 4 and 12 is 12.

Example 2:

Find the LCM of 6 and 8:

** A common misconception may be to multiply the given numbers together. While this would give a multiple, and would sometimes be the lowest (such as with numbers 3 and 4, with an LCM of 12), this is not true for most cases, as we will see here.

6 times-tables: 6, 12, 18, 24, 30, 36, . . .

8 times-tables: 8, 16, 24, 32, 40, . . .

From the lists above, we can see that the lowest (smallest) number (multiple) in both lists (therefore in 'common') is 24.

So the LCM of 6 and 8 is 24.

(Note that by multiplying the given numbers, 6 x 8, we get 48, which is NOT the LCM).

For future lessons and more complex examples we would recap prime numbers and then look at finding the LCM using 'prime factor trees'.

Lowest common multiple, numbers are shared between 2 or more numbers eg. the lowest common multiple of 2 and 4 is 4

Lowest Common Multiple

LCM stands for "Least Common Multiple," and it's a concept in math that's used to find the smallest number that is a multiple of two or more other numbers. 

Think of it like this: If you have two numbers, say 3 and 4, the multiples of 3 are 3, 6, 9, 12, and so on, and the multiples of 4 are 4, 8, 12, 16, and so on. The LCM is the smallest number that appears in the list of multiples of both 3 and 4, which in this case is 12.

So, the LCM helps you find the smallest number that two or more numbers can evenly go into, without leaving a remainder. It's useful in various math problems and calculations.

LCM stands for the Lowest Common Multiple. A multiple of a number is a number in its times tables, for example, 20 is a multiple of 10 because it is 2x10. The LCM of two numbers is the lowest multiple that they both have in common. For example, the LCM of 2 and 5 is 10, because 10 is the lowest number that is a multiple of both 2 and 5.

Lowest common multiple. It's essentially the smallest number that is a multiple of 2 or more numbers. So for example, the smallest number that is a multiple of both 3 and 13 is 39.

Lowest Common Multiple

Given some numbers, could be 2 or more, we need to find the smallest number that is a multiple of all the numbers in your list.

For example -

1) 10 and 15

The lowest common multiple is 30 since, 30 is a multiple of both 10 (i.e. 10 x 3 = 30) and 15 (i.e. 15 x 2 = 30).

2) 6, 8 and 14

The lowest common multiple is 168 since, 168 is a multiple of both 10 (i.e. 6 x 28 = 168), 15 (i.e. 8 x 21 = 168) and 14 (i.e. 14 x 12 = 168).

There is three popular ways of finding this number:

1) Exhaustive method. Make a list of all the multiples of all numbers and find the first common multiple.

2) Finding the prime factors of the all numbers and with that you can find your answer. (You need a whole lesson to understand this)

3) Venn diagram method. (You need a whole lesson to understand this)

LCM stands for lowest common multiple. So if asked for the LCM of two numbers, you are trying to find a the smallest number that can be divided by both numbers with no remainder.

The LCM of two numbers is their lowest common multiple. It is the lowest number than can be divided by these two numbers. For example, the lowest common multiple of 2 and 8, is 8.

LCM stands for "Least Common Multiple".

It is the smallest positive integer that is divisible by two or more given numbers without leaving any remainder.

For example, the LCM of 3 and 4 is 12. This is because 12 is the smallest number that is divisible by both 3 and 4 without leaving a remainder.