The pass rate of parts produced by a factory is 98%, and if 200 parts are processed, what is the number of unqualified products?
某工厂生产的零件合格率是98%，加工200个零件，不合格产品数是多少个．
<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">200 * (1/50)</gadget>
<output>4</output>

<result>4</result>