The perimeter of a rectangle is 24 decimeters, and the ratio of length to width is 2:1. What is the length of the rectangle?
一个长方形的周长是24分米，长与宽的比是2：1，这个长方形的长是多少．
<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">12 * (2/3)</gadget>
<output>8</output>

<result>8</result>