<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Calculator</title>
<style>
body {
text-align: center;
}
input[type="button"] {
width: 50px;
height: 50px;
font-size: 1.5em;
}
</style>
</head>
<body>
<h1>Simple Calculator</h1>
<input type="text" id="display" disabled><br>
<input type="button" value="1" onclick="addToDisplay('1')">
<input type="button" value="2" onclick="addToDisplay('2')">
<input type="button" value="3" onclick="addToDisplay('3')">
<input type="button" value="+" onclick="addToDisplay('+')"><br>
<input type="button" value="4" onclick="addToDisplay('4')">
<input type="button" value="5" onclick="addToDisplay('5')">
<input type="button" value="6" onclick="addToDisplay('6')">
<input type="button" value="-" onclick="addToDisplay('-')"><br>
<input type="button" value="7" onclick="addToDisplay('7')">
<input type="button" value="8" onclick="addToDisplay('8')">
<input type="button" value="9" onclick="addToDisplay('9')">
<input type="button" value="*" onclick="addToDisplay('*')"><br>
<input type="button" value="C" onclick="clearDisplay()">
<input type="button" value="0" onclick="addToDisplay('0')">
<input type="button" value="=" onclick="calculate()">
<input type="button" value="/" onclick="addToDisplay('/')">
<script>
function addToDisplay(value) {
document.getElementById('display').value += value;
}
function clearDisplay() {
document.getElementById('display').value = '';
}
function calculate() {
let result = eval(document.getElementById('display').value);
document.getElementById('display').value = result;
}
</script>
</body>
</html>