The length of the rectangle is 5 decimeters and the width is 20 centimeters. What is the perimeter of the rectangle?
长方形的长是5分米，宽是20厘米，此长方形周长是多少分米．
<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>