The pass rate of the product is 98%, how many waste products are there in 400 products?
产品合格率是98%，400个产品中有多少个废品．
<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">400 * (1/50)</gadget>
<output>8</output>

<result>8</result>