A cylinder is 10 decimeters high. After 2 decimeters are cut off, the surface area is reduced by 12.56 decimeters. What is the original volume of the cylinder?
一个圆柱高10分米，截去2分米后，表面积减少12.56平方分米，这个圆柱原来的体积是多少立方分米？
<gadget id="calculator">12.56 / 2 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 10</gadget>
<output>31.4</output>

<result>31.4</result>