Question

Ballio has a reading goal. He checks 3 boxes of 9 books out from the library. After finishing them, he realizes that he beat his goal by 4 books! Label the tape diagrams to find Ballio's reading goal.

Answer 1

The number of books that Ballio was able to read can be determined by multiplying the number of boxes he checked out and the number of books per box. This is as shown below,
                     N = (3 boxes)(9 books/box)
                       N = 27 books

Since, it is stated that he beat his goal by 4 books, his goal is equal to the calculated number minus 4. 
               Goal = 27 books - 4 books
                Goal = 23 books

ANSWER: 23 books