The radius of the base of a cylindrical log is 0.4m, and the length is 5m. If it is cut into 5 sections, how many square meters will the surface area of these logs increase compared with the original log?
一根圆柱形木料的底面半径是0.4m，长是5m，将它截成5段，这些木料的表面积比原木料增加了多少平方米？
<gadget id="calculator">0.4 ** 2</gadget>
<output>0.16</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">3.14 * 0.16 * 8</gadget>
<output>4.0192</output>

<result>4.0192</result>