pile of 80 tons of goods, 40% of this pile of goods has been transported, how many tons are left?
一堆货物80吨，运走了这堆货物的40%，还剩下多少吨？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">80 * (3/5)</gadget>
<output>48</output>

<result>48</result>