A cuboid steel is 30 decimeters long, and its cross section is a cube with a side length of 0.5 decimeters. If the steel weighs 7.8 kilograms per cubic decimeter, how many kilograms does this steel weigh?
一根长方体钢材长30分米，横截面是一个边长0.5分米的正方体，如果每立方分米钢材重7.8千克，这根钢材重多少千克？
<gadget id="calculator">0.5 * 0.5 * 30 * 7.8</gadget>
<output>58.5</output>

<result>58.5</result>