There is a rectangular wooden board with a circumference of 18 meters. Xiao Ming measures its length to be 6 meters and its width in meters.
有一块长方形木板，周长是18米，小明量出它的长是6米，它的宽是多少米．
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<result>3</result>