What are some common pitfalls when performing calculations with percentage values in PHP?

One common pitfall when performing calculations with percentage values in PHP is forgetting to convert the percentage to a decimal before using it in calculations. To solve this issue, always remember to divide the percentage value by 100 before using it in mathematical operations.

// Incorrect way without converting percentage to decimal
$percentage = 20;
$total = 100;
$result = $total * $percentage; // Incorrect calculation

// Correct way with percentage converted to decimal
$percentage = 20;
$total = 100;
$result = $total * ($percentage / 100); // Correct calculation
echo $result;