In this interactive, students use clues and logic to plot the location of aquatic animals on a Cartesian graph that represents the four cardinal directions. The three riddles in the interactive, including one that requires students to understand rate, have randomized values so that students can practice placing points at different locations on the graph. The accompanying classroom activity provides students with a review of locating points on a Cartesian graph. A response sheet helps students work with the interactive. This resource is part of the Math at the Core: Middle School Collection.