Not sure.  d1 is always the same.  It must be something Format is doing.

Sorry, i've copied the wrong line of code,
this should be it

Console.WriteLine(string.Forma­t{"{0:0.0} - {1}", d1, Math.Round(d1,
1));

However I'm using the same value, this is the result :"1.7- 1.6"

Banker's Rounding can't be used in real life !!!

Check the following example: it's a simple presentation of a ticket.

double[] lines = new double[5];

     //Set some VAT's
     lines[0] = 1.245;
     lines[1] = 1.246;
     lines[2] = 1.241;
     lines[3] = 1.275;
     lines[4] = 1.255;

     //Print and calc total
     double tot = 0;
     foreach (double val in lines) {
       tot += val;
       Console.WriteLine(" {0:0.00}", val);
     }
     Console.WriteLine("-----");
     Console.WriteLine(" {0:0.00}", tot);

     Console.ReadLine();

This is the result :

1,25
1,25
1,24
1,28
1,26
--------
6,26

Now take our your calculator (or excell if you like) an add the 5 lines
manualy !

Your result wil be 6.28.  -> 0.02 difference !!!!!!!!!

If I give this ticket to a client he demands to now where the 0.02 euro
has gone to.

Is there a way I can disable the Banker's Rounding ( set
'MidpointRounding.AwayFromZero' as default) for the entire application
!

Kind Regards
Frank Vanderlinden