The students do exercises, every 25 people line up in a row, the boys line up in 30 rows, and the girls line up in 28 rows. How many more boys than girls.
同学们做操，每25人排成一排，男生排了30排，女生排了28排．男生比女生多多少人．
<gadget id="calculator">30 - 28</gadget>
<output>2</output>

<gadget id="calculator">2 * 25</gadget>
<output>50</output>

<result>50</result>