The sum of the edge lengths of a cuboid and a cube are equal, and the length, width, and height of the cuboid are 7dm, 6dm, and 2dm respectively, so what is the edge length of the cube in dm?
一个长方体和一个正方体的棱长总和相等，已知长方体的长、宽、高分别是7dm、6dm、2dm，那么这个正方体的棱长是多少dm．
<gadget id="calculator">7 + 6 + 2</gadget>
<output>15</output>

<gadget id="calculator">4 / 12</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">15 * (1/3)</gadget>
<output>5</output>

<result>5</result>