Processing 500 parts, the qualified rate is 98%, how many unqualified parts are there?
加工500个零件，合格率是98%，不合格的零件有多少个．
<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<gadget id="calculator">1 - (49/50)</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">500 * (1/50)</gadget>
<output>10</output>

<result>10</result>