A rectangle whose length is 4 decimeters and whose width is 10 centimeters shorter than its length, what is its perimeter?
一个长方形的长4分米，宽比长短10厘米，它的周长是多少分米．
<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

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

<result>14</result>