When a cylindrical steel with a length of 10 decimeters is cut into three cylindrical steels, the surface area increases by 12.56 square decimeters. It is known that steel weighs 7.8 kilograms per cubic decimeter, how many kilograms does this steel weigh?
把一根长10分米的圆柱形钢材截成3段圆柱形钢材时，表面积增加12.56平方分米．已知每立方分米钢材重7.8千克，这根钢材重多少千克？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 * 10 * 7.8</gadget>
<output>244.92</output>

<result>244.92</result>