Instead of telling the students what the concept of order of magnitude is, I let them discover its meaning through a writing prompt. Following is the prompt statement (derived from a Just-In-Time physics question), the students’ results, & the lead up to the definition of order of magnitude and as a bonus the concepts of scientific notation and Significant Figures logically and naturally emerge.

Thanks to JiTT folks, Gregor Novak, Andrew Gavrin, Wolfgang Christian, Evelyn Patterson! 🙂