Lesson 12

In this lesson, students first apply what they have learned about working with exponents (especially powers of ten) to solve rich problems in context. The style of questioning requires students to identify essential features of the problem and persevere to calculate and interpret the solutions in context (MP1, MP2, MP4). Students must attend to precision when considering appropriate units of measurement (MP6).

Next, the lesson formalizes what students have learned by introducing the definition of scientific notation. A number is said to be in scientific notation if it is written as a product of two factors: the first factor is a number greater than or equal to 1, but less than 10; and the second factor is an integer power of 10. This definition does not include negative numbers for simplicity. Students must attend to precision as they decide whether or not numbers are in scientific notation and convert to scientific notation (MP6).

The blackline master for the optional Activity Scientific Notation Matching has three sets of cards. Set A is for the teacher to demonstrate the process, so only one copy of set A is needed. Cut out one set of cards (either set B or set C) for every 2 students. If possible, copy each complete set on a different color of paper, so that a stray slip can quickly be put back.