Data or it didn't happen.

How these work: each sheet rides its unit's phenomenon — the beetle's dash, the green statue, the willow that ate the air. Parts A–D build from warm-up to the good stuff. The answer key lives in the folded section at the bottom of each sheet (and prints on its own page). Second-semester sheets arrive as the units do. Every worksheet Part now has a Learn How doorway with a worked example, an interactive model, and a self-check before students tackle the practice.