Subtract the sum of 2.1 and 2.39 from 4.8, and then divide by 20, what is the quotient?
4.8减去2.1与2.39的和，再除以20，商是多少？
<gadget id="calculator">2.1 + 2.39</gadget>
<output>4.49</output>

<gadget id="calculator">4.8 - 4.49</gadget>
<output>0.31</output>

<gadget id="calculator">0.31 / 20</gadget>
<output>0.0155</output>

<result>0.0155</result>