制做出来是一个五行三列的表格，第一行是标题简易计算器，第二行是第一个数，第三行是第二个数，第四行是计算机结果，第五行是说明步骤，第三列是加减乘除四种运算方法。javascript
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>简易计算器</title>
<style type="text/css">
table{
border:1px solid #10c6c4;
margin:0 auto;
width:450px;
height:180px;
}
tr{
border:1px solid #10c6c4;
}
td{
border:1px solid #10c6c4;
}
th{
border:1px solid #10c6c4;
text-align:center;
height:35px;
}
input[type=button]{
width:33px;
height: 33px;
margin:5px;
background: #11fffc;
border:1px solid #08d0ce;
}
input[type=text]{
width:210px;
height:25px;
margin-left:5px;
padding-left:5px;
}
</style>
<script type="text/javascript">
function yunsuan(op){
var n1=document.getElementById('num1').value;
var n2=document.getElementById('num2').value;
var jieguo=document.getElementById('jieguo').value;
n1=Number(n1);
n2=Number(n2);
switch(op){
case '+':
jieguo=n1+n2;
break;
case '-':
jieguo=n1-n2;
break;
case '*':
jieguo=n1*n2;
break;
case '/':
jieguo=n1/n2;
break;
}
document.getElementById('jieguo').value=jieguo;
}css
</script>
</head>
<body>
<table>
<tr>
<th colspan="3">简易计算器</th>
</tr>
<tr>
<td>第一个数</td>
<td><input type="text" id="num1"></td>
<td rowspan="4">
<input type="button" value="+" onclick="yunsuan('+')"><br>
<input type="button" value="-" onclick="yunsuan('-')"><br>
<input type="button" value="*" onclick="yunsuan('*')"><br>
<input type="button" value="/" onclick="yunsuan('/')"><br>
</td>
</tr>
<tr>
<td>第二个数</td>
<td><input type="text" id="num2"></td>
</tr>
<tr>
<td>结果</td>
<td><input type="text" id="jieguo"></td>
</tr>
<tr>
<td colspan="2">运算方法：输两个数，再选算法</td>
</tr>
</table>
</body>
</html>html