14 Chapter 1 . Thinking Critically Activity 6: Magic Number Tricks PURPOSE Translate verbal phrases into algebraic expressions and reinforce the work backward problem-solving strategy. COMMON CORE SMP SMP 1, SMP 2, SMP 8 MATERIALS Other: Calculator GROUPING Work individually, ting tang 1. Dr. Wonderful, the Mathematical Magician, astounds crowds with his amazing ability How to read people's minds. Here are the directions that he gives to five people in the crowd. Follow Dr. Wonderful's directions and complete the table below. Choose a different number for each person. PERSON 5 1. Pick any number. 2. Multiply by 3. 3. Add 30. 4. Divide by 3. 5. Subtract your original number.Lane 2. Dr. Wonderful tells the people to write their answers on a sheet of paper but not to reveal them to anyone else. He closes his eyes, concentrates deeply, and then claims that he knows each person's answer. Suppose you picked 239. What do you think Dr. Wonderful would say your answer is? Why? 3. To learn why the trick works, let n be the number. Write an algebraic expression for each step and record it below. Step 1: Step 2: Step 3: Step 4: Step 5: The result is Canuright @ 2015 Pearson Education Inc All rights racerved