If the length of a rectangle is 18 cm and the width is 12 cm, what is the perimeter in decimeters?
一个长方形长是18厘米，宽是12厘米，周长是多少分米．
<gadget id="calculator">18 + 12</gadget>
<output>30</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5)</gadget>
<output>6</output>

<result>6</result>