designing of calculator using html and css code example

Example 1: 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>

Example 2: how to make a calculator website HTML

<body>
  
   <center>
    <h1 class="text-danger">Calculator</h1> 
    <p class="q">Type in the numbers to be added, separate them with commas (,). If 'Invalid' shows, you have not used a number, please clear the box and type numbers</p>
   </center>

    <center>
    <h3 style="font-family: Lucida Sans; color: lightseagreen">Add</h3>
    <input class="addinput" type="text">
   <button class="add" style="font-family: Lucida Sans; background-color: lightsalmon">ADD</button>
   <p class="p" style="background-color:lightpink">Sum is <span class="result"></span></p>
   </center>
 
<center>
    <h3 style="font-family: Lucida Sans; color: lightseagreen">Multiply</h3>
  <input class="multiplyinput" type="text">
  <button class="multiply" style="font-family: Lucida Sans; background-color: lightsalmon">MULTIPLY</button>
   <p class="p" style="background-color:lightpink"></p>>Product is <span class="product"></span></p>
</center>

<center>
        <h3 style="font-family: Lucida Sans; color: lightseagreen">Subtract</h3>
    <input class="subtractinput" type="text">
    <button class="subtract" style="font-family: Lucida Sans; background-color: lightsalmon">SUBTRACT</button>
     <p class="p" style="background-color:lightpink"></p>>Difference is <span class="difference"></span></p>
  </center>

  <center>
        <h3 style="font-family: Lucida Sans; color: lightseagreen">Divide</h3>
    <input class="divideinput" type="text">
    <button class="divide" style="font-family: Lucida Sans; background-color: lightsalmon">DIVIDE</button>
     <p class="p" style="background-color:lightpink"></p>>Quotient is <span class="quotient"></span></p>
  </center>
  
   <script src="calculator.js"></script>

</body>