A rectangular parallelepiped steel is 10 meters long and its cross-section is a square with side length 5 decimeters. If each cubic meter of steel weighs 9.8 kilograms, how many kilograms does this piece of steel weigh?
一根长方体钢材长10米，横截面是边长为5分米的正方形．如果每立方米的钢材重9.8千克，这根钢材重多少千克？
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * (1/2) * 10 * 9.8</gadget>
<output>24.5</output>

<result>24.5</result>