Master Wang has processed 500 parts, and the pass rate is 96%. How many are unqualified?
王师傅加工了500个零件，合格率为96%，不合格的有多少个？
<gadget id="calculator">96 / 100</gadget>
<output>24/25 = around 0.96</output>

<gadget id="calculator">1 - (24/25)</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">500 * (1/25)</gadget>
<output>20</output>

<result>20</result>