How do I find the sum of top 10 rows of a column in a datatable in asp .net

  DataTable dtGetadata=GetDataTable();

//call method GetDataTable();

public DataTable GetDataTable ()
       {
            DataTable dtData=new DataTable();
           //Fill datatable with data

           int Total=0;

           for(int i=0;i<10;i++)
           {
               Total+=Convert.ToInt32(dtData.Rows[i]["amount"]);

           }
               dtData.Rows.Add("","Total",Total);

           return dtData;

       }

var sum = datatable.AsEnumerable().Take(10)
    .Sum(x => x.Field<int>("Amount" ));</int>

var Total = yourdatatable.AsEnumerable().Take(10)
    .Sum(x => x.Field<datatype>("Amount" ));
//here first convert the DataTable to IEnumerable<t> objects. As this object can be used for LINQ expression .Then make a Sum function to get the result . here datatype may be decimal or int. Give the datatype for corresponding "Amount" field .
</t></datatype>