The inner diameter of the water pipe is 2 cm and the velocity of water in the pipe is 8 cm per second. How many milliliters of water flow out of this pipe per second?
自来水管的内直径是2厘米，水管内水的流速是每秒8厘米．这根水管每秒流出水多少毫升？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 8</gadget>
<output>25.12</output>

<result>25.12</result>