This Instructional Activity is a part of the Lesson 13, Unit 1, Grade 8. We have learned why scientific notation is indispensable in science. This means that we have to learn how to compute and compare numbers in scientific notation. We have already done some computations, so we are ready to take a closer look at comparing the size of different numbers. There is a general principle that underlies the comparison of two numbers in scientific notation: Reduce everything to whole numbers if possible. To this end, we recall two basic facts.