Simple to make four function HTML math calculator

HyperText Markup Language (HTML) is the main markup language for displaying web pages and other information that can be displayed in a web browser.

 

Here is the code used to make the calculator.

<form name="calculator">
<!-- form the display to match the keypad -->
<table border="4" cellpadding="1" bordercolor="#FFFFFF" bgcolor="#73B27B" cellspacing="2" width="222">
<tr>
<td>
<input type="text" size="25" length="25" value="" name="ans" style="background:beige;color:black;">
</td>
</tr>
</table>
<!-- form the keypad with buttons in a table -->
<table border="4" cellpadding="2" bordercolor="#FFFFFF" cellspacing="2" width="150" bgcolor="#73B27B">
<tr>
<td align="center">
<input type="button" value=" 7 " name="seven" onClick="document.calculator.ans.value+='7'">
</td>
<td align="center">
<input type="button" value=" 8 " name="eight" onClick="document.calculator.ans.value+='8'">
</td>
<td align="center">
<input type="button" value=" 9 " name="nine" onClick="document.calculator.ans.value+='9'">
</td>
<td align="center">
<input type="button" value=" / " name="divide" onClick="document.calculator.ans.value+='/'">
</td>
</tr>
<tr>
<td align="center">
<input type="button" value=" 4 " name="four" onClick="document.calculator.ans.value+='4'">
</td>
<td align="center">
<input type="button" value=" 5 " name="five" onClick="document.calculator.ans.value+='5'">
</td>
<td align="center">
<input type="button" value=" 6 " name="six" onClick="document.calculator.ans.value+='6'">
</td>
<td align="center">
<input type="button" value=" * " name="multiply" onClick="document.calculator.ans.value+='*'">
</td>
</tr>
<tr>
<td align="center">
<input type="button" value=" 1 " name="one" onClick="document.calculator.ans.value+='1'">
</td>
<td align="center">
<input type="button" value=" 2 " name="two" onClick="document.calculator.ans.value+='2'">
</td>
<td align="center">
<input type="button" value=" 3 " name="three" onClick="document.calculator.ans.value+='3'">
</td>
<td align="center">
<input type="button" value=" - " name="subtract" onClick="document.calculator.ans.value+='-'">
</td>
</tr>
<tr>
<td align="center">
<input type="button" value=" C " name="clear" onClick="document.calculator.ans.value=''">
</td>
<td align="center">
<input type="button" value=" 0 " name="zero" onClick="document.calculator.ans.value+='0'">
</td>
<td align="center">
<input type="button" value=" = " name="equal"
onClick="document.calculator.ans.value=eval(document.calculator.ans.value)">
</td>
<td align="center">
<input type="button" value=" + " name="add" onClick="document.calculator.ans.value+='+'">
</td>
</tr>
</table>
</form>