Systematic listing and counting in prekindergarten through grade 2 -- Bucket of buttons: explorations in sorting and counting -- Systematic listing and counting in grades 3 through 5 -- Bindu Bear's boutique: counting in an organized way -- Vertex-edge graphs in prekindergarten through grade 2 -- From here to there: explorations on vertex-edge graphs -- Vertex-edge graphs in grades 3 through 5 -- Maps, conflicts, and vertex-edge graphs -- Iteration and recursion in prekindergarten through grade 2 -- Exploring picture sequences -- Iteration and recursion in grades 9 through 12 -- Exploring sequences -- Looking back and looking ahead.