A trapezoidal piece of land has an upper base of 500 meters, a lower base of 1 km, and a height of 200 meters. On average, 200 kilograms of vegetables are harvested per hectare. How many tons of vegetables are harvested in this vegetable field?
一块梯形的土地，上底是500米，下底是1千米，高是200米．平均每公顷收菜200千克，这块菜地一共收菜多少吨．
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">500 + 1_000</gadget>
<output>1_500</output>

<gadget id="calculator">200 / 2 / 10_000</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">200 / 1_000</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1_500 * (1/100) * (1/5)</gadget>
<output>3</output>

<result>3</result>