# Greatest Common Divisor Calculator

If you're looking to find the highest common factor of two integers, then you'll need to use a Greatest Common Divisor (GCD) calculator. A GCD calculator is a tool that allows you to find the largest positive integer that divides two or more integers without leaving a remainder. This tutorial will show you how to use a GCD calculator and explain the formula used to find the GCD.

 Enter the Numbers [seperated by a space]: 5 10 15 20
 Greatest Common Divisor

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## Step 1: Input the Numbers

The first step in using a GCD calculator is to input the numbers for which you want to find the GCD. For example, if you want to find the GCD of 18 and 24, you would input those two numbers into the calculator.

## Step 2: List the Factors

The next step is to list the factors of each of the inputted numbers. Factors are numbers that divide a given number without leaving a remainder. For example, the factors of 18 are 1, 2, 3, 6, 9, and 18. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24. Listing the factors can help you determine the common factors of the two inputted numbers.

## Step 3: Find the Common Factors

After listing the factors of both numbers, you should identify the factors that are common to both. These are the numbers that divide both inputted numbers without leaving a remainder. In our example, the common factors of 18 and 24 are 1, 2, 3, 6.

## Step 4: Determine the GCD

Finally, to find the GCD, you need to identify the largest common factor. In our example, the largest common factor of 18 and 24 is 6. Therefore, the GCD of 18 and 24 is 6.

### GCD Formula

The formula for finding the GCD of two numbers, a and b, is:

GCD(a,b) = GCD(b, a mod b)

where "a mod b" is the remainder when a is divided by b.

## Conclusion

Using a GCD calculator can save you time and effort in finding the highest common factor of two integers. By following the steps outlined in this tutorial and using the GCD formula, you can easily find the GCD of any two numbers.

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