If a rectangle increases its length and width by 1/2, then the area of the current rectangle is equal to the original rectangle.
一个长方形，把它的长和宽分别增加(1/2)，则现在长方形的面积是原来长方形的多少．
<gadget id="calculator">9 / 4</gadget>
<output>9/4 = around 2.25</output>

<result>9/4 = around 2.25</result>