A square iron block with a side length of 10 cm is forged into a rectangular parallelepiped iron bar with a side length of 5 cm in cross section. What is the length of this iron bar?
把一块棱长10厘米的正方体铁块，锻造成横截面边长是5厘米的正方形的长方体铁条，这个铁条长是多少？
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">10 / 25</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">10 * 10 * (2/5)</gadget>
<output>40</output>

<result>40</result>