This article is aimed at teachers already experienced with activities involving small, student-collected data sets and who are now ready to begin working with large, online data sets collected by scientists and engineers. The authors discuss challenges, instructional strategies, and sources of appropriate lesson plans. With guidance, plus online data and newly acquired big data skills, students can find evidence for some of the big ideas of science, rather than having to accept those ideas on authority from a teacher or textbook. They can conduct investigations about places and circumstances where they may never go, such as the bottom of the ocean. They can explore phenomena that are global in scope and span years in time, becoming a part of the community of users of that same data, and perhaps even make important discoveries of their own. Students' facility with complex data will be useful in a growing array of professions, from auto mechanics to health care, plus a necessary prerequisite for careers in science and engineering.