There is a pile of 20 tons of sand on the construction site, 1/8 of the total is removed on the first day, and 40% is removed on the second day, how many tons are left?
工地有一堆沙20吨，第一天运走总数的(1/8)，第二天运走40%，还剩多少吨？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/8) + (2/5)</gadget>
<output>21/40 = around 0.525</output>

<gadget id="calculator">20 * (21/40)</gadget>
<output>21/2 = around 10.5</output>

<gadget id="calculator">20 - (21/2)</gadget>
<output>19/2 = around 9.5</output>

<result>19/2 = around 9.5</result>