A pile of 240 tons of goods, (2/5) of the total number is transported away for the first time, and (1/4) of the total number is transported away for the second time, how many tons of this pile of goods are left unshipped?
一堆货物240吨，第一次运走总数的(2/5)，第二次运走总数的(1/4)，这堆货物还剩下多少吨没有运？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (2/5) - (1/4)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">240 * (7/20)</gadget>
<output>84</output>

<result>84</result>