What is the perimeter of a rectangle 2 decimeters long and 15 centimeters wide?
长2分米，宽15厘米的长方形，它的周长是多少厘米．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 + 15</gadget>
<output>35</output>

<gadget id="calculator">35 * 2</gadget>
<output>70</output>

<result>70</result>