The Mailbox? Superbook Grade 3 is your complete resource to reinforce and enhance your third-grade curriculum for an entire year of success. From management tips to arts-and-crafts ideas and lessons that reinforce basic skills, you can turn to this book for grade-appropriate, original, and fun-filled ideas. This great collection of year-round materials is the one resource that you can't be without - ; a great back-to-school buy! Grade 3. 320 pages.