using System;

class Program
{
    static void Main()
    {
// Divide the first number by the second number.
int operand1 = 100;
int operand2 = 345;

// Incorrect division for double:
double number1 = operand1 / operand2;
Console.WriteLine(number1);

// Correct division for double:
double number2 = (double)operand1 / operand2;
Console.WriteLine(number2);

// Incorrect division for double:
double number3 = (double)(operand1 / operand2);
Console.WriteLine(number3);

// Correct division for double:
double number4 = (double)operand1 / (double)operand2;
Console.WriteLine(number4);

// Correct division for double:
double number5 = operand1 / (double)operand2;
Console.WriteLine(number5);
    }
}

Output

0
0.289855072463768
0
0.289855072463768
0.289855072463768

Note: Be aware of the zero output!

Reference: http://www.dotnetperls.com/divide