The area of a circle is 20m**2, if it is divided into 5 parts on average, what is the area of 4 parts in m**2?
一个圆的面积是20m**2，把它平均分成5份，其中4份的面积是多少m**2．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">20 * (4/5)</gadget>
<output>16</output>

<result>16</result>