If a cylindrical steel material with a length of 2 meters and a diameter of 4 decimeters at the bottom is cut into 4 small cylinders, how many square decimeters will the surface area increase?
把一根长2米，底面直径4分米的圆柱形钢材截成4个小圆柱，表面积增加了多少平方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 6</gadget>
<output>75.36</output>

<result>75.36</result>