A pile of coal weighs 20 tons. A truck has transported it 4 times, and the remaining half has not been transported. How many tons does this truck transport on average each time? (Solution problems of column equations)
一堆煤重20吨，一辆货车运了4次，还剩一半没有运，这辆货车平均每次运多少吨？(列方程解应用题)
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">20 - 10</gadget>
<output>10</output>

<gadget id="calculator">10 / 4</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>