Use 84cm iron wire to form a rectangle, the ratio of length to width is 2:1, what is the area of this rectangle?
用84cm的铁丝围成一个长方形，长与宽的比是2：1，问这个长方形的面积是多少？
<gadget id="calculator">84 / 2</gadget>
<output>42</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">42 * (2/3)</gadget>
<output>28</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">42 * (1/3)</gadget>
<output>14</output>

<gadget id="calculator">28 * 14</gadget>
<output>392</output>

<result>392</result>