In a trapezoidal orchard, the upper base is 80 meters, the lower base is 60 meters, and the height is 30 meters. If each fruit tree occupies an area of 10 square meters, how many fruit trees are there in this orchard?
一个梯形果园，上底是80米，下底是60米，高是30米，如果每棵果树占地10平方米，这个果园共有多少果树？
<gadget id="calculator">80 + 60</gadget>
<output>140</output>

<gadget id="calculator">30 / 2 / 10</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">140 * (3/2)</gadget>
<output>210</output>

<result>210</result>