There is a piece of iron with a side length of 4 decimeters, and it is now going to be melted and cast into a cuboid with a cross-sectional area of 10 square decimeters. What is the length of this cuboid?
有一块棱长4分米的铁块，现要把它熔铸成一个横截面积是10平方分米的长方体．这个长方体的长是多少分米？
<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">4 * 4 * (2/5)</gadget>
<output>32/5 = around 6.4</output>

<result>32/5 = around 6.4</result>