After sawing a 10-meter-long cuboid log into two pieces, the surface area increases by 40dm**2 compared to the original one. What is the original volume of this log in cubic meters?
把一根长10米的长方体木料锯成两段后，表面积比原来增加了40dm**2，这根木料原来的体积是多少立方米？
<gadget id="calculator">40 / 2 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 10</gadget>
<output>2</output>

<result>2</result>