Use a rope to form a rectangle with a length of 6.4 meters and a width of 16 decimeters. If it is changed into a square, what is the area of the square?
用一根绳子正好围成一个长6.4米，宽16分米的长方形，如果把它改围成正方形，那么正方形的面积是多少？
<gadget id="calculator">6.4 + 1.6</gadget>
<output>8</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">8 * (1/2)</gadget>
<output>4</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>