Texas Instruments: Numb3 Rs: Coded Messages

Based off of the hit television show NUMB3RS, this lesson uses matrices (inverse and multiplication) to decode messages hidden within digital pictures -- a process known as steganography. This method of hidden communication is known to have been used by terrorists, bringing a sense of realism to the lesson. Students will encode and decode messages using matrix operations on their calculators. It is assumed that students are already familiar with these manipulations.