This Instructional Activity is a part of the Lesson 13, Unit 7, Grade 8. Students work in pairs to complete Exercises 1-11. The first exercise may be used to highlight the process of answering and explaining the solution to each question. An emphasis should be placed on students' ability to explain their reasoning. Consider allowing students to use a calculator to check their work, but all decimal expansions should be done by hand. At the end of the Exploratory Challenge, consider asking students to state or write a description of their approach to solving each exercise.