This interactive unit includes 3 lessons and 3 extension activities. In lesson 1, students explore the need for standardized units of measurement and the benefit of the metric system. Students will engage in a pre-lesson activity measuring classroom items in the unit of straw to stimulate a discussion about measurement. In the second lesson, students explore the tools of the metric system, learning to correctly use scales, graduated cylinders, and even rulers. Finally, in the third lesson st