Page Chapter 5. Working with Databases, Page 54

Location on the page: 
Getting Results for Paged Display
Error: 

The line reading...$result = pager_query(db_rewrite_sql($sql), 0, 10); ... is incorrect. According to the drupal API documentation, the second paramater to the pager query is the number of query results to display per page. This number is used in a division arithmatic operation somewhere in Drupal. When it is set to 0, a divide by zero error is return.

Correction: 

The default number of page results is 10, so simply stating...$result = pager_query(db_rewrite_sql($sql));... works just fine. If a user wanted 25 results per page he can have $result = pager_query(db_rewrite_sql($sql));

Description of the Error: 

Divide by Zero error