How many ways can you calculate it? There are 600 exercise books in the stationery store. After selling some, there are 4 packs left, each pack of 25 books. How many packs are sold?
你能用几种方法来计算？文具店有600本练习本，卖出一些后，还剩4包，每包25本，卖出多少包？
<gadget id="calculator">600 / 25</gadget>
<output>24</output>

<gadget id="calculator">24 - 4</gadget>
<output>20</output>

<result>20</result>