One hundred green-eyed logicians have been imprisoned on an island by a mad dictator. Their only hope for freedom lies in the answer to one famously difficult logic puzzle. Can you solve it? Alex Gendler walks us through this green-eyed...

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...