Complete Trails (scavenger hunt) version includes the Desk Version which can be done in groups or used for students who have been absent, and the walk-around version. Students first estimate then use their estimate to determine if their answer is reasonable. Trails are self-checking so the students are able to work independently of the teacher. There is also a riddle to be solved as they fill in their answers. A fun activity to practice mental math, multiplication, and cooperative work with partners or groups.