The fourth set of books from Gather Round Homeschool of the Letters and Numbers program is called In the Air. The Teacher's Guide has daily reading that is perfect for shorter attention spans and includes 13 weeks (over 3 months) of content! Like the entire Letters and Numbers series, this covers all of your subjects and takes you through a Preschool/Early Kindergarten level in content for math, science, and language arts. Hands on, engaging, and open and go, finally a program that you don't have to think about or prepare for! Set includes the teachers guide and workbooks A and B, new, never used.