Calculadora

<!-- para estudos -->
<center>
<form name="Calc">
<table border=3>
<tr>
<td>
<input type="text" name="Input" size="16">
<br>
</td>
</tr>
<tr>
<td>
<input type="button" name="um" value=" 1 " onClick="Calc.Input.value += '1'">
<input type="button" name="dois" value=" 2 " onClick="Calc.Input.value += '2'">
<input type="button" name="tres" value=" 3 " onClick="Calc.Input.value += '3'">
<input type="button" name="somar" value=" + " onClick="Calc.Input.value += ' + '">
<br>
<input type="button" name="quatro" value=" 4 " onClick="Calc.Input.value += '4'">
<input type="button" name="cinco" value=" 5 " onClick="Calc.Input.value += '5'">
<input type="button" name="seis" value=" 6 " onClick="Calc.Input.value += '6'">
<input type="button" name="subtrair" value=" - " onClick="Calc.Input.value += ' - '">
<br>
<input type="button" name="sete" value=" 7 " onClick="Calc.Input.value += '7'">
<input type="button" name="oito" value=" 8 " onClick="Calc.Input.value += '8'">
<input type="button" name="nove" value=" 9 " onClick="Calc.Input.value += '9'">
<input type="button" name="multiplicar" value=" x " onClick="Calc.Input.value += ' * '">
<br>
<input type="button" name="apagar" value=" c " onClick="Calc.Input.value = ''">
<input type="button" name="zero" value=" 0 " onClick="Calc.Input.value += '0'">
<input type="button" name="igual" value=" = " onClick="Calc.Input.value = eval(Calc.Input.value)">
<input type="button" name="divisao" value=" / " onClick="Calc.Input.value += ' / '">
<br>
</td>
</tr>
</table>
</form>
</center>
<!-- fonte: PlugWeb -->