Don't confuse a value with its string representation.
Mathematically, 1.1, 1.10, 1.100, ..., 1.10000000000 are all the
same value. On presentation to the end user, you can chose to represent the number of decimals you want.
double value = 1.1;
Console.WriteLine(value.ToString("F1"));
Console.WriteLine(value.ToString("F2"));
Console.WriteLine(value.ToString("F3"));
Console.WriteLine(value.ToString("F4"));