For example: math.php
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>math.php</title>
</head>
<body>
<?php
$additionanswer = 100+10;
//Online Calculator
Print("<h1> Online Calculator </h1>");
//Display math output
print ("100 + 10 = " . (100 + 10). " Addition <br>");
print ("100 - 10 = ". (100-10) ." Subtraction <br>");
print("100 * 10 = ". (100*10) ." Multiplication <br>");
print("100 / 10 = ". (100/10) ." Division <br>");
print("99 % 10 = ". (99%10) ." Modulus (the remainder!) <br>");
?>
</body>
</html>
</body>
</html>