Показать добавленную стоимость в mysql

Hello Awesome Programers there!
	I need your help please. I have problem in my codes, I don't know how I could make the things I want to be in my tables results.
	
	The result from mysql it should be like this: (tvalue means total value)
        
  th_name1      | th_name2    | th_name3    | th_name4    | th_name_5   | th_name6    
 -------------------------------------------------------------------------------------
 th_scope_row1 |td_tvalue2.1 |td_tvalue3.1 |td_tvalue4.1 |td_tvalue5.1 |td_tvalue6.1 
 th_scope_row2 |td_tvalue2.2 |td_tvalue3.2 |td_tvalue4.2 |td_tvalue5.2 |td_tvalue6.2 
 th_scope_row3 |td_tvalue2.3 |td_tvalue3.3 |td_tvalue4.3 |td_tvalue5.3 |td_tvalue6.3 


Example:
      In mysql or in database:
(Grade 5)
ID | Grade level | Math_Subj | English_Subj | History_Subj | P.E_Subj |Science_Subj
-------------------------------------------------------------------------------------
1  | Grade 5     |  16       |   10         |   5          |   8      | 3
2  | Grade 5     |   2       |    6         |   8          |   3      | 5

(Grade 4)
ID | Grade level | Math_Subj | English_Subj | History_Subj | P.E_Subj |Science_Subj
-------------------------------------------------------------------------------------
1  |  Grade 4     |   8       |   11         |   8          |   5      | 4
2  |  Grade 4     |   2       |    4         |   2          |   3      | 1

(Grade 3)
ID | Grade level | Math_Subj | English_Subj | History_Subj | P.E_Subj |Science_Subj
-------------------------------------------------------------------------------------
1  |  Grade 3     |   4       |    9         |   5          |   8      | 9
2  |  Grade 3     |   7       |    4         |   3          |   1      | 2


    Table result and shows in page:
      Grade level | Math_Subj | English_Subj | History_Subj | P.E_Subj |Science_Subj
      ------------------------------------------------------------------------------
      Grade 5     |  18       |  16          |  13          |  11      |  8
      Grade 4     |  10       |  15          |  10          |   8      |  5
      Grade 3     |  11       |  13          |   8          |   9      |  11

<?php
$con=mysqli_connect("localhost","test","abdub","test_table");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$result = mysqli_query($con,"SELECT id,( Grade level +  Math_Subj + English_Subj + History_Subj + P.E_Subj ) AS total, Grade level, Math_Subj, English_Subj, History_Subj, P.E_Subj, FROM `Record_show");

echo "<table border='1'>
<tr>
    <th>ID</th>
    <th>Grade level</th>
    <th>Math_Subj</th>
    <th>English_Subj</th>
    <th>History_Subj</th>
    <th>P.E_Subj</th>
    <th>Science_Subj</th>
</tr>";

while($row = mysqli_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $row['Grade_5'] . "</td>";
echo "<td>" . $row['Grade_4'] . "</td>";
echo "<td>" . $row['Grade_3'] . "</td>";
echo "</tr>";
}
echo "</table>";

mysqli_close($con);

?>