A square steel is 50 decimeters long. Its cross section is a square with a side length of 0.2 decimeters. It is known that 1 cubic decimeter weighs 7.8 kilograms. How many kilograms does this square steel weigh?
一根方钢长50分米，它的横截面是一个边长为0.2分米的正方形，已知1立方分米重7.8千克，这根方钢重多少千克？
<gadget id="calculator">50 * 0.2 * 0.2 * 7.8</gadget>
<output>15.6</output>

<result>15.6</result>