The students of Zhangzhuang Primary School line up to do exercises. If there are 28 people in each row, there will be 15 more people after standing in 18 rows. How many people are there in Zhangzhuang Primary School?
张庄小学的同学排队做操，如果每排站28人，站成18排后还多15人．张庄小学一共有多少人？
<gadget id="calculator">28 * 18</gadget>
<output>504</output>

<gadget id="calculator">504 + 15</gadget>
<output>519</output>

<result>519</result>