The master processes 20 parts every day, and the apprentice processes 16 parts every day. How much less does the apprentice process than the master every day?
师傅每天加工20个零件，徒弟每天加工16个零件，每天徒弟比师傅少加工百分之几？
<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<gadget id="calculator">4 / 20</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>