Book Set 2-3 (15 books): Developmentally-appropriate book sets for the classroom are an integral part of TOOLBOX™ Lesson Plans K-3 and 4-6. The books serve as an entryway to understanding the 12 Tools. Books for each Tool have been carefully selected and organized into developmental sets (K-1, 2-3, and 4-6). Our Standard Implementation Package includes a full set of literature for each classroom teacher. A Book Set K-6 is also available as a shared library resource for students, as well as counselors, RSP, and other teachers to utilize.