A class has 500 tables and 2/5 times as many books as the number of tables in the class are on top of each table. What's the total number of books in the class?
If there are 2/5 times as many books as the number of tables in the class on top of each table, there are 2/5*500 = 
<gadget id="calculator">2/5*500</gadget>
<output>200</output>
200 books.
Since the class has 500 tables with 200 books on top of each, there are 500*200 = 
<gadget id="calculator">500*200</gadget>
<output>100_000</output>
100000 books.

<result>100_000</result>