Ready for a fun and exciting way for your students to practice their addition fact-fluency to 20? With only 20 minutes of prep time, The Case of the Missing Valentines is for you! Students will love working in teams to 'crack the case', using the process of elimination, and help Paulie Penguin find his missing valentine cards! This resource includes: 1. Teacher Directions :)2. The Case of the Missing Valentines short story3. "Who", "When", and "Where" display posters4. 5 Addition to 20 task car