Master subtraction with Launch, Stage 1, Book 2. Book 2 applies some of the same self-correcting puzzle structures to subtraction as Book 1 did for addition. Book 2 also pairs number lines with these puzzle structures to facilitate understanding. Launch is a uniquely structured set of self-correcting puzzles which emphasize how numbers combine. These puzzles have been designed to engage and challenge the student, while promoting independence. They are perfect for classroom differentiation since puzzles often have multiple answers. Practicing math with Launch is not only enjoyable, but allows students to make further insights by themselves.Six different types of puzzles are included in Stage 1, Book 2.