For a rectangular orchard 100 meters long and 65 meters wide, if the length and width are multiplied by 2, how many hectares will the area of the orchard increase?
一个长100米，宽65米的长方形果园，如果长与宽都乘2，那么果园的面积增加多少公顷？
<gadget id="calculator">65 / 10_000</gadget>
<output>13/2_000 = around 0.0065</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">100 * (13/2_000) * 3</gadget>
<output>39/20 = around 1.95</output>

<result>39/20 = around 1.95</result>