Cody was reading through his favorite book series.  The series was 54 books in total.  If Cody read 6 books the first week, and 3 books the second week and then 9 books every week after that.  How many weeks did it take Cody to read his series?
Cody needs to read 54 books - 6 books - 3 books = 
<gadget id="calculator">54-6-3</gadget>
<output>45</output>
45 books.
Cody read 9 books each week after = 45 books / 9 books per week = 
<gadget id="calculator">45/9</gadget>
<output>5</output>
5 weeks.
Cody read for 1 week + 1 week + 5 weeks = 
<gadget id="calculator">1+1+5</gadget>
<output>7</output>
7 weeks total.

<result>7</result>