how to create a simple calculator in html
<!DOCTYPE html>
<html lang="en">
<head>
<style>
.contain{
display: flex;
}
#display{
width: 98%;
}
.mathButtons{
width: 100px;
height: 40px;
background-color: rgb(0,0,0,0.3);
color: white;
}
.mathButtons:hover{
background-color: DodgerBlue;
}
#clearButton:hover{
background-color: orangered;
}
#container{
width: 430px;
height: 300px;
}
.buttondigits{
background-color: black;
color: white;
height: 40px;
width: 100px;
}
#clearButton{
width: 100px;
height: 40px;
background-color: rgb(0,0,0,0.3);
font-weight: bold;
}
.buttondigits:hover {
background-color: gray;
}
</style>
<title> standard calculator </title>
<meta charset="utf-8">
<link rel="stylesheet" href="cal.css"/>
</head>
<body>
<div class="container">
<fieldset id="container">
<form name="calculator">
<input type="text" id="display" name="display" readonly>
<br>
<br>
<br>
<div class="contain">
<input class="buttondigits" type="button" value="7" onclick="calculator.display.value += '7'">
<input class="buttondigits" type="button" value="8" onclick="calculator.display.value += '8'">
<input class="buttondigits" type="button" value="9" onclick="calculator.display.value += '9'">
<input class="mathButtons" type="button" value="+" onclick="calculator.display.value += '+'">
</div>
<div class="contain">
<input class="buttondigits" type="button" value="4" onclick="calculator.display.value += '4'">
<input class="buttondigits" type="button" value="5" onclick="calculator.display.value += '5'">
<input class="buttondigits" type="button" value="6" onclick="calculator.display.value += '6'">
<input class="mathButtons" type="button" value="-" onclick="calculator.display.value += '-'">
</div>
<div class="contain">
<input class="buttondigits" type="button" value="1" onclick="calculator.display.value += '1'">
<input class="buttondigits" type="button" value="2" onclick="calculator.display.value += '2'">
<input class="buttondigits" type="button" value="3" onclick="calculator.display.value += '3'">
<input class="mathButtons" type="button" value="*" onclick="calculator.display.value += '*'">
</div>
<div class="contain">
<input id="clearButton" class="button" type="button" value="C" onclick="calculator.display.value = ''">
<input class="buttondigits" type="button" value="0" onclick="calculator.display.value += '0'">
<input class= "mathButtons" type="button" value="=" onclick="calculator.display.value = eval(calculator.display.value)">
<input class="mathButtons" type="button" value="/" onclick="calculator.display.value += '/'">
</div>
</form>
</fieldset>
</div>
</body>
</html>