After 40% of the 40 tons of flour are sold, how many tons are left?
40吨面粉卖出40%后，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">40 * (3/5)</gadget>
<output>24</output>

<result>24</result>