C# double addition - strange behaviour

Question

public static void Main()
{
    Dictionary values = new Dictionary();
    values.Add(\"a\", 0.002);
    values.Add(\"b\",         


        

Answer 1

The problem with double/float's is that they are binary numbers, aka 1000110.10101001 internally, and therefore only represent an approximate representation of your values.

Read Jon Skeet's explanation: Difference between decimal, float and double in .NET?