Everyday Mathematics: Study Links Grade 5

Purchased this for my 10 yr old son for extra math practice to use in conjunction with his Everyday Math Reference Book. Received the book very quickly and it was in excellent condition. Purchased the book used but it appeared new in appearance. Once he began to work problems, I began to notice that many of the pages were missing. The book was designed to have print on both the front and back of each page. After about page 20 the book had many pages that only had print on one side. So basically only ended up purchasing an incomplete addition of the Study Links Manual.The material that was in the manual was very good and went right along with the hardback reference book.