# Ratio manipulation in C++ with examples

Hello everyone, in this tutorial, we will be studying ratio manipulation in C++. C++ has a header file separately to deal with operations related to fractions. There are many template aliases for ratio manipulation.

## Ratio manipulation in C++

We can perform addition, subtraction, multiplication, and division operation on fractions using <ratio> header file. Let’s discuss these operations one by one.

In order to add two ratios, we use ratio_add template alias as you can see in the below program. The output given by this is in the simplest form. It returns two values num and den respectively. num represents the numerator and den represents the denominator. Have a look at this code.

```#include <iostream>
#include <ratio>
using namespace std;

int main()
{
typedef ratio<1, 4> r1;
typedef ratio<1, 8> r2;

cout << "Result of 1/4 + 1/8 is: " << r3::num << "/" <<r3::den;

return 0;
}```

The output of the above program:

`Result of 1/4 + 1/8 is: 3/8`

### Subtracting ratios

As we used ratio_add template alias for the addition of two fractions, similarly we can use ratio_subtract subtract one ratio from another. Again the output is in the simplest form. The return values are num and den respectively.

See the below code.

```#include <iostream>
#include <ratio>
using namespace std;

int main()
{
typedef ratio<1, 4> r1;
typedef ratio<1, 8> r2;

typedef ratio_subtract<r1, r2> r3;

cout << "Result of 1/4 - 1/8 is: " << r3::num << "/" <<r3::den;

return 0;
}```

Output:

`Result of 1/4 - 1/8 is: 1/8`

### Multiplying ratios

To get the multiplication of two fractions or ratios we can use ratio_multiply. The below code explains the working of this template alias. The return values are the same as in the above two operations.

```#include <iostream>
#include <ratio>
using namespace std;

int main()
{
typedef ratio<1, 4> r1;
typedef ratio<1, 8> r2;

typedef ratio_multiply<r1, r2> r3;

cout << "Result of 1/4 * 1/8 is: " << r3::num << "/" <<r3::den;

return 0;
}```

Output:

`Result of 1/4 * 1/8 is: 1/32`

### Division of ratios

To divide a ratio by another ratio we have to use ratio_divide template alias. It returns the same values as the above and the result is in the simplest form. See the code.

```#include <iostream>
#include <ratio>
using namespace std;

int main()
{
typedef ratio<1, 4> r1;
typedef ratio<1, 8> r2;

typedef ratio_divide<r1, r2> r3;

cout << "Result of (1/4) / (1/8) is: " << r3::num << "/" <<r3::den;

return 0;
}```

Output:

`Result of (1/4) / (1/8) is: 2/1`

Thank you. Hope it was helpful.

Also read: Fraction Module in Python