The perimeter of a rectangle is 28 decimeters, its length is 8 decimeters, and its width should be how many decimeters.
长方形的周长28分米，它的长是8分米，宽应该是多少分米．
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">14 - 8</gadget>
<output>6</output>

<result>6</result>