This lesson has students cut out dinosaur cards from the provided worksheets. Each card contains a picture of the dinosaur, its name, the period (Triassic or Cretaceous) and its length. Students are asked to order the cards from smallest to largest and then compute the mean, median and mode of the distributions. Dinosaurs changed dramatically from the Triassic to Cretaceous period. Dinosaurs were very small during the Triassic period but became huge by the time the Cretaceous period arrived. This activity allows students to do real world analysis of dinosaur lengths and engage in critical thinking by using easily understood manipulatives.