5 tons of goods, 20% of it is transported each time, how many times can it be transported.
5吨货物，每次运走它的20%，多少次可以运完．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / (1/5)</gadget>
<output>5</output>

<result>5</result>