Cut a cylinder with a base diameter of 4 decimeters and a height of 5 decimeters into an approximate cuboid. What is the volume of the cuboid in cubic decimeters?
把一个底面直径4分米，高5分米的圆柱切拼成一个近似长方体，长方体体积是多少立方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3.14 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">6.28 * 2 * 5</gadget>
<output>62.8</output>

<result>62.8</result>