Divide column with external value

//get System.Data.EnumerableRowCollection
var values = dt.AsEnumerable();
//get total from <code>myVal</code> field
int total = values.Sum(r=>r.Field<int32>("myVal"));
//do calculations using linq query
var PercSum = from v in values 
              select new
              {
                  Value = v.Field<int32>("myVal"),
                  SumOfValue = total,
                  Percentage = Convert.ToDecimal(v.Field<int32>("myVal")) / Convert.ToDecimal(total)
               };
//list values 
Console.WriteLine("Value | Sum | Percentage");
foreach (var p in PercSum )
{
    //
    Console.WriteLine("{0} | {1} | {2}", p.Value.ToString(), p.SumOfValue.ToString(),p.Percentage);
}

DataTable tbl = new DataTable("TestTable");

DataColumn c = new DataColumn("Col1", typeof(Int32));
tbl.Columns.Add(c);
c = new DataColumn("Col2", typeof(Int32));
tbl.Columns.Add(c);

// create expression data column and add to table
// the third parameter defines the expression.
c = new DataColumn("Col3", typeof(Decimal), "Col1 / Col2");
tbl.Columns.Add(c);

for (int i = 1; i <= 10; i++)
{
    DataRow r = tbl.NewRow();
    r["Col1"] = i;
    r["Col2"] = (i + 10);
    // don't set Col3 as the expression will automatically used to set the value
    tbl.Rows.Add(r);
}