The perimeter of a rectangle is 16 cm, its width is 2 cm, what is its length?
长方形的周长是16厘米，它的宽是2厘米，它的长是多少．
<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<result>6</result>