A batch of goods is 20 tons, and (1/4) of it is transported away each time, how many times it is transported.
一批货物20吨，每次运走它的(1/4)，多少次运完．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / (1/4)</gadget>
<output>4</output>

<result>4</result>