Lesson Title: 8.SP.A.3 Lesson Using and Interpreting Linear Models
Course: Common Core 8
Date: _____________ Teacher(s): ____________________
Start/end times: ________________
Lesson Standards/Objective(s): What mathematical skill(s) and understanding(s) will be developed? Which
Mathematical Practices do you expect students to engage in during the lesson?
8.SP.A.3 Use the equation of a linear model to solve problems in the context of bivariate measurement data,
interpreting the slope and intercept.
MP3: Construct viable arguments and critique the reasoning of others.
MP4: Model with mathematics.
MP6: Attend to precision.
Lesson Launch Notes: Exactly how will you use the
first five minutes of the lesson?
Students will complete a KWL resource sheet to share
their knowledge of predictions.
Lesson Closure Notes: Exactly what summary activity,
questions, and discussion will close the lesson and
connect big ideas? List the questions. Provide a
foreshadowing of tomorrow.
The KWL resource sheet will allow students to summarize
their understanding. In addition, the homework
assignment will give students an opportunity to solidify
their understanding of using the equation of a line of best
fit.
Lesson Tasks, Problems, and Activities (attach resource sheets): What specific activities, investigations,
problems, questions, or tasks will students be working on during the lesson? Be sure to indicate strategic
connections to appropriate mathematical practices.
Note: Depending on length of the class period, this lesson may take two class periods to complete.
1. Warm-Up: Ask students to complete a KWL resource sheet about predictions. Students can explain their
understanding of the word, describe how to make predictions, or mention topics appropriate for making
predictions. Make a large KWL chart on the document camera or chalkboard of the class responses. Focus on
the topics that will be covered in the lesson.
2. Shark Tank: Show students a clip of Shark Tank, a television show on ABC. This can be accessed at
www.abc.com. Be sure to view the video ahead of time to ensure it is appropriate. (If the video cannot be
accessed, lead a discussion about investing in businesses or let students research investors). “Shark Tank” is a
show in which entrepreneurs bring their ideas to potential investors and try to convince them to invest in their
company or product. Inform students that they will soon be entering the “shark tank” and they will need to
support their business by using mathematics.
3. Business Activity: Students will pair up and create a business model to convince an investor to help them expand
the sales of a product. Students can determine the product and a name for the product.
 Students will graph the data they are given and find the equation of a line of best fit using graphing
calculators. (Look for evidence of MP4 and MP6.)
 Students will answer prediction questions about the data, using their equation for the line of best fit.
(Note: The teacher may need to review solving a problem with an equation or guide students through the
first question on the activity.) (Look for evidence of MP3.)
 Students will use PowerPoint, iMovie, chart paper, Inspiration, or other formats to create a presentation
of their work.
 If there is time, students can present their model to a group of teachers or students (the “shark tank”).
Lesson Title: 8.SP.A.3 Lesson Using and Interpreting Linear Models
Course: Common Core 8
Date: _____________ Teacher(s): ____________________
Start/end times: ________________
Otherwise, post student projects throughout the room and allow students to view other projects.
4. Group Discussion:
When the projects are completed, conduct a group discussion about the validity of predictions and factors
that should be considered. Ask questions such as the following: (Look for evidence of MP3.)
 Do you think your predictions are valid? Why or why not?
 What factors might cause profits to be higher than predicted?
 What factors might cause profits to be lower than predicted?
 When can predictions be considered valid?
 When should the validity of predictions be questioned?
Conclude this discussion by asking students what the equation of the line of best fit tells them about the data.
Specifically, what does the slope represent? How would the slope change if the data changed? What does
the y-intercept represent? What does the y-intercept represent on the graph? (This could be done during the
next day if necessary).
5. Interpretations: The PowerPoint can be used in a variety of ways for students to discuss the slope and y-intercept
of an equation of a line of best fit. Options are listed below: (Look for evidence of MP3.)
 Students will be shown the equation of a linear situation and its context on the overhead and will write
their interpretation of the slope or y-intercept on a white board. Students will hold these up for the
teacher to see and the teacher will lead a discussion about the students’ responses
 Students will be divided into groups of four and each group will be given a copy of one of the situations
from the PowerPoint. Each group will come up with a description of the slope and y-intercept. Groups
will present these to the class and ask for feedback from other students to adjust their descriptions.
 Students will be given the four situations on a resource sheet and asked to pick one of interest to them.
They will write descriptions for the slope and y-intercept. Students will write their descriptions on the
chalkboard under their situation. Students who chose the same situation will discuss their interpretations
together and determine the best description. They can then present these to the class.
 Students will go through the PowerPoint slides at a computer with a partner. They will discuss and
agree on interpretations and bring these to a class discussion when all students are finished.
This should lead to the conclusion that slope is the amount the y-value is increasing or decreasing per change in
the x-value and the y-intercept is the initial amount (when x is zero).
6. Lesson Closure: Students will complete their KWL resource sheet to share what they learned during the lesson.
Encourage them to discuss the business activity as well as the slope and y-intercept interpretations. There is also
a graphic organizer that could be used in the next lesson to summarize findings. This organizer can be
completed on the computer through Inspiration or can be copied and given to students to write on.
Optional Extension Activity: Ask students to change the graphs from their business models to display the data
differently (change the intervals on either axis to show slower/faster profit growth). (Look for evidence of MP4.)
Evidence of Success: What exactly do I expect students to be able to do by the end of the lesson, and how will I
measure student success? That is, deliberate consideration of what performances will convince you (and any outside
observer) that your students have developed a deepened and conceptual understanding.
Students need to be able to explain the meaning of the slope and y-intercept in the context of a linear situation,
calculate predictions using a line of best fit equation, and discuss the accuracy of predictions. Evidence of success
will be measured through student participation, successful completion of business models, answers to interpretation
activity, and successful completion of the KWL resource sheet.
Notes and Nuances: Vocabulary, connections, anticipated misconceptions (and how they will be addressed), etc.
Lesson Title: 8.SP.A.3 Lesson Using and Interpreting Linear Models
Course: Common Core 8
Date: _____________ Teacher(s): ____________________
Start/end times: ________________
Vocabulary: Slope, y-intercept, line of best fit equation, prediction, slope as a rate of change
Typical misconceptions: Make sure that students use their equation to make predictions instead of just the table of
values
Resources: What materials or resources are essential
for students to successfully complete the lesson tasks or
activities?
Homework: Exactly what follow-up homework tasks,
problems, and/or exercises will be assigned upon the
completion of the lesson?
KWL resource sheets
Shark Tank video (www.abc.com)
Paper, markers, colored pencils
Computers, access to software
Business model resource sheets
Graphing calculators
PowerPoint presentation with linear models or paper
copies for students
White boards
White board markers
Homework activity resource sheets
Carnegie Learning Algebra I Textbook (if available)
Students will complete a homework assignment on linear
models and predictions. They will be asked to share their
answers with the class during the next lesson.
Lesson Reflections: How do you know that you were effective? What questions, connected to the lesson
standards/objectives and evidence of success, will you use to reflect on the effectiveness of this lesson?
What concepts do students have a strong understanding of?
What concepts/skills do students need additional support/reinforcement?
Students will share their homework answers the next day-were they able to accurately interpret slopes and yintercepts? Did students make predictions appropriately and judge the accuracy of the prediction with strong
argumentative writing?
Howard County Public Schools Office of Secondary Mathematics Curricular Projects has
licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0
Unported License.