I used this lesson for part of my National Board Certification. It is one of the best lessons that I have ever written, and I highly recommend it. This works extremely well year after year, and most of my department has adopted it.
Description: This lesson is designed for use AFTER learning how to graph and how to write different forms of a linear equation. Students will look at photos of not-really -celebrities in a PowerPoint slide show and guess their ages. (We cannot use actual celebrity photos because of copyright issues. However, these photos are extremely creative, interesting, and attention-grabbing.) The slide show will then show the actual ages, which the students will write down beside their estimated age for each person. Students will create a scatter plot, determine a best-fit line through two of the points, and write the equation of this line in various forms. Students will then use this equation to make predictions. The optional part two of this assignment is designed for students to work in groups in order to compare and contrast their best-fit lines. Students will have to choose which group member was the best age-guesser after first discovering what variables they need to consider in order to determine who to award first prize. Students also find the exact equation for their best-fit line using a graphing calculator and choose the group member whose estimate of the best-fit line best matched.
Part One: PowerPoint and a projector to show it
Part Two (Optional): One graphing calculator per group for section two.
First, you need to know how to play a PowerPoint slide show. Load the file into your computer, and make sure that everything works so that students can see the slides. Give each student a copy of the activity, and you're ready to go. For the optional day 2 activity, assign groups in advance, and give each group a graphing calculator.
Directions: Show PowerPoint to students. (The PowerPoint has been made so that it will automatically advance once you pass the instructions slides.) Students must first guess the age of each person, recording guesses in the x column of the chart. Then, they should record actual ages (given to them in the slide show) in the y column. “Part 1” should be given to students to work on individually. (I give this to them as homework.) “Part 2” is designed for groups of 3-4 students, and a graphing calculator is required for #7-10.
How I use this in my classroom:
I start the class by creating an x/y chart with each student's height & shoe size. We graph this and choose a line of best fit. Then, we determine the slope, slope-intercept equation, and standard equation. I then ask the class to determine the height of someone with a size 2 shoe, as well as the shoe size of someone who is 90 inches tall. I then begin this activity by handing out "part one" and showing the slide show, assigning the remainder of the activity for homework. This creates some wonderful discussions the next day, especially if I can do the optional graphing calculator activity.