A cylindrical cistern with a volume of 1256 cubic meters and a diameter of 20 meters at the mouth of the cistern is how many meters deep is this cistern?
一个容积是1256立方米的圆柱形蓄水池，池口直径20米，这个蓄水池有几米深呢？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">1_256 / 314</gadget>
<output>4</output>

<result>4</result>