How to divide integers and get value with decimal part?

This has to do with typing. You are dividing 2 integers, so you get an integer, if you want a result that is not integer you need to divide numbers that are not integers, you can do a cast , it's safe to do something that increases precision: / p>

using static System.Console;

public class Program {
    public static void Main() {
        int soma = 7;
        int cont = 2;
        double media = (double)soma / (double)cont;
        WriteLine(media);
    }
}

See running on .NET Fiddle . And no Coding Ground . Also I put it in GitHub for future reference .

You do not need to convert the two operands, if one of them is double , the result will already be double to ensure that it has no loss of precision.

It does not make sense for you to use type int which will always return integer.

You can use type decimal or double depending on what you are going to do:

decimal media = 0 , soma = 7 , cont = 2;
media = soma / cont; //retorna 3.5

Here is another simpler and easier way:

double soma = 7;
double cont = 2;
var media = soma / cont; //retorna 3.5

Or you can use Convert.ToDouble() or Convert.ToDecimal() .

Double media = 0;
int soma = 7;
int cont = 2;
media = Convert.ToDouble(soma) / cont; // retorna 3.5

public class Program {
        public static void Main() {
            double soma = 7;
            double cont = 2;
            double media = soma / cont;
            WriteLine(media);
        }
    }