Are you looking for a fun CSI Math Mystery Detective activity to engage your students in adding, subtractingn and multiplying decimals and 2 digit by 2 digit multiplication? Then this is for you.Capture your students attention with this CSI alien-themed math mystery by taking them on a journey with comparing decimals, adding and subtracting decimals, multiplying decimals, and solving multiplication problems with 2 digits, Students narrow down the suspects by completing the activities and puzzle