A rectangular vegetable field is 20 meters wide, and its length is more than its width (1/4). What is the area of this vegetable field?
一块长方形菜地，宽是20米，长比宽多(1/4)，问这块菜地的面积是多少？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">20 * (5/4) * 20</gadget>
<output>500</output>

<result>500</result>