In a batch of products, there are 196 qualified products and 4 rejected products. What is the rejected product rate?
在一批产品中，合格的有196个，废品有4个，废品率是多少．
<gadget id="calculator">196 + 4</gadget>
<output>200</output>

<gadget id="calculator">4 / 200</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

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

<result>1/50 = around 0.02</result>