February 11 of the Mystery Year is the birthday of Thomas Edison. Math clues for finding the year involve determining the price for electricity based on a rate per kWh, dimensional analysis, inequalities, and divisibility. The clues provide math problems related to Edison's inventions.Your Zip download includes printable/digital PDFs:1-page printable Student Puzzle, also prepped for Easel1-page Answer Key with sample solutions1-page version of puzzle with expanding form fields – use with Acrobat