A square steel stud with a side length of 0.5 meters is used to forge a rectangular parallelepiped steel with a side length of 0.2 meters in cross section. What is the length of the steel?
用一个棱长是0.5米的正方形钢柸锻造成一个截面是边长0.2米的正方形的长方体钢材，钢材的长是多少？
<gadget id="calculator">0.5 * 0.5 * 0.5</gadget>
<output>0.125</output>

<gadget id="calculator">0.2 * 0.2</gadget>
<output>0.04</output>

<gadget id="calculator">0.125 / 0.04</gadget>
<output>3.125</output>

<result>3.125</result>