A rectangular vegetable field is 10 meters long and 6 meters wide, what is its perimeter?
一块长方形菜地，长10米，宽6米，它的周长是多少？
<gadget id="calculator">10 + 6</gadget>
<output>16</output>

<gadget id="calculator">16 * 2</gadget>
<output>32</output>

<result>32</result>