1. Lesson 1

1.4. Discover

Mathematics 20-1 Module 1

Module 1: Sequences and Series

 

Discover
 
Try This 1

 

This shows a photo of a teenager sitting at a desk completing an academic test.

Digital Vision/Thinktock

 

Study the arrangement of marbles in each figure, and then answer the questions. Remember to save your responses in your course folder—you will need those responses in the upcoming Share 1.

 

This shows an illustration of three arrangements of marbles. The first arrangement has four rows, with 4, 3, 2, and 1 marble in each row. The second arrangement has four rows, with 5, 4, 3, and 2 marbles in each row. The third arrangement has four rows, with 6, 5, 4, and 3 marbles in each row.

  1. If the pattern continues, how many marbles would each of the next two figures have? How did you determine your answer?

  2. Describe how you would find the number of marbles in figure 20. Use your method from question 1 to determine the number of marbles.

  3. Describe how you would find the number of marbles in figure 100. Use your method from question 1 or find a new method to determine the number of marbles.

  4. Was your method for determining the number of marbles in figure 20 different from your method used for figure 100? If yes, why did you choose a different method? If no, can you think of another method that might be more efficient? Explain.

course folder Save your work in your course folder.

 

Share 1
 

If you do not have access to a discussion board, another student, or an appropriate partner with whom to share your work, talk to your teacher. For more information on Share discussions, refer to the Course Introduction or contact your teacher.

 

Share your responses from Try This 1 with a partner or group.

  • Compare the answers for questions 1, 2, and 3. Are the answers given by your classmates similar to your own? Explain reasons for any differences.

  • Compare and discuss your method for solving questions 2 and 3 with methods used by your classmates.

course folder If your teacher requires, you may need to place a summary of your Share discussion in your course folder.

 

You may have found that there really are a variety of ways to solve the problem. As you move through the lesson, you will encounter other strategies you can use when you revisit the Try This 1 problem later in the lesson.