There are 500 tons of cement in the warehouse, 12% of the total is removed for the first time, and 20% of the total is removed for the second time. How many tons of cement are left?
仓库里有水泥500吨，第一次运走总数的12%，第二次运走总数的20%．还剩下多少吨水泥？
<gadget id="calculator">12 / 100</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (3/25) - (1/5)</gadget>
<output>17/25 = around 0.68</output>

<gadget id="calculator">500 * (17/25)</gadget>
<output>340</output>

<result>340</result>