Completed Math board. With student work to the left of Marty the Math Detective board directions. The file in front of Marty says 'Confidential' and, in the file, there are worksheets that have math problems that involve decimals. Students are to multiply, add, and subtract the numbers is order to solve the mystery. When they solve the problem, they lift up the flap on the matching window to reveal a letter. There are spaces to record their letter and answer on the worksheet so they can find out who the suspect is.