In a trapezoidal wheat field. The upper bottom is 230 meters long, the lower bottom is 270 meters long, and the height is 60 meters. A total of 12 tons of wheat are harvested. How many tons of wheat are harvested on average per hectare? ．
在一块梯形麦田．上底长230米，下底长270米，高是60米，共收小麦12吨．平均每公顷收小麦多少吨？．
<gadget id="calculator">270 + 230</gadget>
<output>500</output>

<gadget id="calculator">60 / 2 / 10_000</gadget>
<output>3/1_000 = around 0.003</output>

<gadget id="calculator">500 * (3/1_000)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">12 / (3/2)</gadget>
<output>8</output>

<result>8</result>