shortcut method

THE BELOW GIVEN METHOD OF FINDING LCM OF NUMBERS IS ONE OF THE BEST IF PRACTICED BETTER.

Here is an example.

Suppose you are given a question:

Find the LCM of 12, 18?

Now here is the shortcut formula for solution of LCM of two numbers or more numbers given above.

Step 1:
pick the highest of the given numbers of whom we have to find the LCM.

In the above example question, pick 18 as it is highest among 12 and 18.

Step 2: check it whether it can be divided by other number(s). if you can divide it, then it means your answer is that highest number. But if you cannot divide it by other number(s), then follow the step 3 given below.

In the above example, check 18 whether it can be divided by 12 or not. Since 18 cannot be divided by 12, so move on to step 3.

Step 3: multiply the highest number to 2,3,4,… and so on till you find that number which can also be divided by the other number(s).

In the above problem, multiply 18 to 2 in your mind, it is equal to 36. Now check it whether it can be divided by 12. Since 36 can be divided by 12,

so 36 is the LCM of 12,18.

Now let us take another example.

Find the LCM of 2, 3, 5?

Shortcut formula: pick 5 since it is highest number among the three. Now check it whether it can be divided by 2 and 3. 5 cannot be divided by 2 and 3. Now think of 5x2= 10 (since you know the table of 5). Check whether it can be divided by 2 and 3. It again cannot be divided. Now think of 15 then 20 then 25 then 30. Now 30 is that number which can be divided by 2 and 3.

So the LCM of 2, 3, 5 is 30.

When you practice this method, you can easily solve LCM of numbers in seconds in your mind.