The diameter of the outlet of a tube of toothpaste is 5 mm. Each squeeze of 1 cm long toothpaste can be used 40 times. What is the volume of this toothpaste in cubic millimeters (pi is taken as 3.14)
一支牙膏的出口处直径为5毫米，每次挤1厘米长的牙膏，可以用40次，这支牙膏的容积是多少立方毫米(圆周率取3.14)
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) ** 2</gadget>
<output>25/4 = around 6.25</output>

<gadget id="calculator">3.14 * (25/4) * 1 * 40</gadget>
<output>785</output>

<result>785</result>