避免在我的结果中添加累积量

I have this code that perfoms a while loop on a two rowed table, whereby each row is multiplied by each others corresponding values. The problem i'm having is that $grade_point is showing all the multiplicated values for each row and adding them cummulatively. But i actually need the summation of the multiplicated values.

$grade_point = 0;
while ($row8 = mysql_fetch_assoc($query8)) {
  if ($row8['score'] >= 70) {
    $score = 5;
  }elseif ($row8['score'] >= 60) {
    $score = 4;
  }elseif ($row8['score'] >= 50) {
    $score = 3;
  }elseif ($row8['score'] >= 45) {
    $score = 2;
  }elseif($row8['score'] >= 40) {
    $score = 1;
  }else{
    $score = 0;
  }
  $grade_point += $score * $row['course_unit'];
  echo "$grade_point";
}

You echo inside the loop ;) You need to echo the value outside the loop if you only want to see the end result