Page 74 - IM_Algebra1_FL Print Sample.pdf

• 45 student said they prefer pencil and lined paper. For each part, explain or show your reasoning.
1. How many students prefer using pencil more than pen?
2. How many students prefer using pen and unlined paper? 3. How many students prefer using pencil and unlined paper?
Student Response
1. 60 since there are 100 students total and 40 who prefer pen, so the rest must prefer pencil and .
2. 30 since there are 40 students total who prefer pen and 10 of those prefer lined paper, so the rest must prefer unlined paper ( ).
3. 15 since there are 45 students who prefer unlined paper and just determined there are 30 who prefer pen and unlined paper, so the rest ( ) must prefer pencil and unlined paper.
Activity Synthesis
The purpose of this discussion is for students to share the di erent ways that they approached this problem and to introduce how to represent data using a two-way table.
Select previously identi ed students in the order listed in the narrative to share their answers and methods for nding values that worked.
Point out that a categorical variable represents data which can be divided into groups or categories. In this example, utensil and paper preference are two categorical variables.
Demonstrate how to solve the problem in the warm-up by creating and completing a two-way table.
prefer pen
prefer pencil
total
prefer lined paper
10
45
55
prefer unlined paper
30
15
45
total
40
60
100
Ask students
• “Why is this table an e ective method for solving this problem?” (It is e ective because it keeps track of all of the information that we know and don’t know in a way that is organized to show the relationship between each piece of information.)
Unit 3 Lesson 1: Two-way Tables 7