calculations using variables in html table cell

I am generating html tables dynamically. Each table has multiple columns and various calculations need to be done on each column and displayed at the bottom of the column. I am including the code from one table below. The $tablerow generates the table data and the $tablefooter generates the rows at the bottom that will include the calculated values. Preceding the $tablerow declaration, I have declared some variables and done calculations. I then included these in the $tablefooter to display the calculated values. This works fine. However, I have many other calculations on other columns in other tables. Using this method, I would have to declare many new variables just for calculations. I am wondering if there is a way to do these calculations directly in the table cells. I am pretty new to PHP and have not used calculations much. $sumpop += $POP; $sumadultcirc += $ADULTCIRC; $sumjuvcirc += $JUVCIRC; $tablerow[1] = "<tr><td>" . $row["name"] . "</td>" . "<td>$POP<td>$ADULTCIRC</td> <td>$JUVCIRC</td><td>$TOTCIRC</td><td>$CIRCPERCAP</td><td>$TOTREF</td><td>$R EFPERCAP</td></tr>"; $tablefooter[1] = "<tr><td><b>Table total</b></td><td><b>$sumpop</b></td> <td><b>$sumadultcirc</b></td><td><b>$sumjuvcirc</b></td><td><b>$TOTCIRC</b>< /td> <td><b>$CIRCPERCAP</b></td><td><b>$TOTREF</b></td><td><b>$refpercap</b></td> </tr> <tr><td><b>Table average or per capita</b></td><td><b>$POPAV</b></td> <td><b>$ADCIRCAV</b></td><td><b>$JUDCIRCAV</b></td><td><b>$TOTCIRCAV</b></td > <td><b>$CIRCPERAV</b><td><b>$TOTREFAV</b><td><b>$REPERAV</b></td></tr>";