A rectangular parallelepiped of steel is 5 meters long and its cross-section is a square with a side length of 0.4 meters. If 1 cubic meter of steel weighs 7.8 kg, how much does this steel weigh?
一根长方体钢材，长5米，横截面是一个边长0.4米的正方形．如果1立方米的钢材重7.8千克，这根钢材重多少千克？
<gadget id="calculator">0.4 * 10 * 0.4 * 10 * 5 * 10 * 7.8</gadget>
<output>6_240</output>

<result>6_240</result>