There are 25 boys in Class 1, and 80% of the girls are boys. How many girls are there?
六一班有男生25人，女生是男生的80%．女生有多少人？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">25 * (4/5)</gadget>
<output>20</output>

<result>20</result>