Use a rope to form a square with a side length of exactly 6.5 decimeters. If the perimeter is changed to a rectangle of 8 decimeters, how many square meters should the area of the rectangle be? (column equation solution)
用一根绳子围成一个正方形，边长恰好为6.5分米．如果改围成长为8分米的长方形，所围成长方形的面积应是多少平方米？(列方程解答)
<gadget id="calculator">6.5 * 4</gadget>
<output>26</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">26 - 16</gadget>
<output>10</output>

<gadget id="calculator">10 / 2 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">8 * (1/20)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>