When Xiao Ming calculated (4+△)*5, he ignored the parentheses. How much difference did his calculated result have from the correct one?
小明计算(4+△)*5时，把小括号看掉了，他这样算出的结果与正确结果相差多少．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<result>16</result>