A rectangular plank is 8 meters long and 1 meter wide. What is the perimeter of the plank?
一块长方形木板，长是8米，宽是1米，这个木板的周长是多米？
<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>