piece of steel with a length of 8dm has a cross-section of a square with a side length of 0.5dm. It is known that the steel weighs 7.8 kg per cubic decimeter. How many kilograms does this piece of steel weigh?
一段长8dm的钢材，横截面是边长为0.5dm的正方形，已知每立方分米的钢材重7.8千克，这段钢材重多少千克？
<gadget id="calculator">0.5 * 0.5 * 8 * 7.8</gadget>
<output>15.6</output>

<result>15.6</result>