Students are introduced to classification through progressive activities. Initially, the teacher models the task by classifying buttons. Students then devise a classification scheme for paper clips. Subsequent activities use objects brought from... (View More) home or the playground by students. The objects are assigned to two categories: natural or human-made, then classified as solid, liquid, gas or a combination. Simple bar graphs are used throughout to compare classification data. (View Less)

This worksheet, suitable for pre-readers, directs students to categorize pictures as sources of either natural or artificial light. The resource is part of the teacher's guide accompanying the video, NASA Why Files: The Case of the Mysterious Red... (View More) Light. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide. (View Less)