The shape of a fish pond is trapezoidal. Its upper base is 18 meters, its lower base is 42 meters, and its height is 12 meters. There are 320 fish fry per square meter. How many fish fry are needed in this fish pond?
一个鱼塘的形状是梯形，它的上底是18米，下底是42米，高是12米，每平方米放鱼苗320尾，这个鱼塘共需鱼苗多少尾？
<gadget id="calculator">18 + 42</gadget>
<output>60</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">60 * 6 * 320</gadget>
<output>115_200</output>

<result>115_200</result>