copy this html code
<!DOCTYPE html>
<html>
<head>
<title>Calculator</title>
<style>
body {
font-family: Arial, sans-serif;
}
.calculator {
width: 200px;
background-color: #f2f2f2;
padding: 10px;
border-radius: 5px;
margin: 0 auto;
}
.calculator input[type="text"] {
width: 100%;
margin-bottom: 10px;
padding: 5px;
font-size: 18px;
}
.calculator .buttons {
display: grid;
grid-template-columns: repeat(4, 1fr);
grid-gap: 5px;
}
.calculator button {
padding: 10px;
font-size: 16px;
background-color: #e0e0e0;
border: none;
cursor: pointer;
}
.calculator button:hover {
background-color: #d0d0d0;
}
.calculator .equal-button {
grid-column: span 2;
}
.calculator .clear-button {
grid-column: span 3;
}
</style>
</head>
<body>
<div class="calculator">
<input type="text" id="result" readonly>
<div class="buttons">
<button onclick="addToScreen('7')">7</button>
<button onclick="addToScreen('8')">8</button>
<button onclick="addToScreen('9')">9</button>
<button onclick="addToScreen('/')">/</button>
<button onclick="addToScreen('4')">4</button>
<button onclick="addToScreen('5')">5</button>
<button onclick="addToScreen('6')">6</button>
<button onclick="addToScreen('*')">*</button>
<button onclick="addToScreen('1')">1</button>
<button onclick="addToScreen('2')">2</button>
<button onclick="addToScreen('3')">3</button>
<button onclick="addToScreen('-')">-</button>
<button onclick="addToScreen('0')">0</button>
<button onclick="addToScreen('.')">.</button>
<button onclick="calculate()">=</button>
<button onclick="addToScreen('+')">+</button>
<button onclick="clearScreen()" class="clear-button">C</button>
</div>
</div>
<script>
function addToScreen(value) {
document.getElementById('result').value += value;
}
function calculate() {
var result = eval(document.getElementById('result').value);
document.getElementById('result').value = result;
}
function clearScreen() {
document.getElementById('result').value = '';
}
</script>
</body>
</html>
