Use a 72 cm long iron wire to make a cuboid teaching aid. It is known that the length is 7 cm, the height is 6 cm, and the width is in cm.
用一根长72厘米的铁丝做一个长方体的教具，已知长是7厘米，高是6厘米，宽是多少厘米．
<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">7 + 6</gadget>
<output>13</output>

<gadget id="calculator">18 - 13</gadget>
<output>5</output>

<result>5</result>