Visual c# decimal places and currency

Question

I'm a novice with C# and I've read a few other questions about decimals but still goes over my head , so I ask how do i 1) Change Average Inventory to english pounds as i have read questions but they all seem to be static ones where as mine are changing.

Average inventory = (Beginning inventory + Ending inventory) / 2.0

Turnover = Cost of goods sold / Average inventory

http://i42.tinypic.com/17bvpv.png

So All im trying to achieve is changing Average Inventory to currency a NO decimal places , possibly rounding. Changing TurnOver to 1 Decimal Place.

These are some codes i found but there meaning is beyond me

        //decimal.Round = something.ToString("$#,2") ;
       // Decimal.Round = resultDecimal = decimal.Round(amountDecimal, 2);

       // decimal.Round(DecimalValue, Integer = .1);

        //decimal.Round(1.25M, 1, MidpointRounding.AwayFromZero);  
       // double after1 = Math.Round(before1, 1, MidpointRounding.AwayFromZero);

       // Math.Round(3.44, 1); //Returns 3.4.
        //decimal.Round(1, MidpointRounding.AwayFromZero);

Answer 1

decimal d = 100000.123456M;
var s = d.ToString("C0", new CultureInfo("en-GB")); //gives £100,000

Where the C indicated currency formatting and the 0 indicated the nr. of decimal places.

Answer 2

Try this:

using System.Globalization;

...

decimal d = 100000.123M;
NumberFormatInfo nfi = new CultureInfo("en-GB", false).NumberFormat;
nfi.CurrencyDecimalDigits = 0;
var s = d.ToString("C", nfi);