Computational thinking" (CT) is still a relatively new term in the lexicon of learning objectives and science standards. The term was popularized in an essay by Wing, who said, "To reading, writing and arithmetic, we should add computational thinking to every child's analytical ability." Agreeing with this premise, in 2013 the authors of the Next Generation Science Standards (NGSS) included "mathematical and computational thinking" as one of eight essential science and engineering practices that K-12 teachers should strive to develop in their students. There is not yet widespread agreement on the precise definition or implementation of CT, and efforts to assess CT are still maturing, even as more states adopt K-12 computer science standards. In this article we will try to summarize what CT means for a typical introductory (i.e., high school or early college) physics class. This will include a discussion of the ways that instructors may already be incorporating elements of CT in their classes without knowing it.