Grade 8 Math: Data and Probability unit
Students learn to tell when a question needs one-variable or two-variable data, collect and organize their own continuous data, and choose the right graph, including scatter plots. They describe relationships as strong, weak, positive or negative, draw lines of best fit to make predictions, and learn to spot misleading graphs and weak conclusions. The probability lessons compare theoretical and experimental results using Venn and tree diagrams. The unit ends with students building an infographic from a data set.
What's included
- Unit overviewBig ideas, expectations by code, learning goals and success criteria
- Day-by-day calendar16 days planned, including catch-up and review days
- 10 three-part lessonsMinds On, Action and Consolidation, with timings, questions to ask and common mistakes
- Student worksheets with answer keys89 questions in all, every numeric answer checked by software
- Diagnostic and quick checksA Day 1 diagnostic and 3 quick checks to adjust your teaching
- Performance task and rubric“Screen Time and Sleep infographic”, with a rubric across all four achievement chart categories
- Unit test and answer key26 marks, sorted by achievement chart category
- AccommodationsSupports for students with IEPs, English language learners, and extensions
Look inside
These are real pages from the unit.
Day-by-day calendar
| Day | Lesson or assessment | Expectations |
|---|---|---|
| 1 | Diagnostic and unit launch | |
| 2 | Lesson 1: One-variable and two-variable data | D1.1 |
| 3 | Lesson 2: Collecting continuous data | D1.2 |
| 4 | Lesson 3: Scatter plots (Quick check 1) | D1.3 |
| 5 | Lesson 4: Choosing the best graph | D1.3 |
| 6 | Lesson 5: Describing relationships and lines of best fit | D1.5 |
| 7 | Lesson 6: Misleading graphs (Quick check 2) | D1.6 |
| 8 | Lesson 7: Questioning conclusions | D1.6 |
| 9 | Lesson 8: What makes a good infographic | D1.4 |
| 10 | Lesson 9: Theoretical and experimental probability (Quick check 3) | D2.1 |
| 11 | Lesson 10: Venn diagrams and tree diagrams | D2.1 |
| 12 | Catch-up and conferencing day (reteach from quick checks) | All |
| 13 | Performance task: Screen Time and Sleep infographic (part 1) | D1.3, D1.5 |
| 14 | Performance task: Screen Time and Sleep infographic (part 2) | D1.4, D1.6, D2.1 |
| 15 | Review: stations and practice test | All |
| 16 | Unit test | All |
Lesson 1: One-variable and two-variable data
Learning goal: We are learning to tell when a question needs one-variable data and when it needs two-variable data.
Success criteria:
- I can sort questions into one-variable and two-variable.
- I can write a question that needs two-variable data.
Minds On (10 min)
- Ask two questions: "What is the most common bedtime in our class?" and "Do students who go to bed later sleep less?" Students discuss what data each needs.
Action (35 min)
- Define one-variable and two-variable data; show that two-variable data come in pairs from the same person or thing.
- Groups sort question cards and explain each choice.
- Students complete the worksheet.
Consolidation (15 min)
- Students share their own two-variable questions; the class predicts what the relationship might be.
- Exit: "Write one question about our school that needs two-variable data."
One or two variables?
Write 1 or 2 for each question and explain.
- What is the favourite sport of Grade 8 students?
- Do students who sleep more get higher test scores?
- How tall are the students in our class?
- Does the daily temperature affect ice cream sales?
- Explain when you need two-variable data.
- Write a question about your school that needs two-variable data.
Answer keys with worked steps are in the Teacher Guide.
Performance task: Screen Time and Sleep infographic
A school wellness committee collected (made-up) data from 12 students: hours of screen time per day and hours of sleep per night. The pairs are: (1, 9.5), (1.5, 9.2), (2, 9), (2.5, 8.8), (3, 8.5), (3, 8.9), (4, 8.1), (4.5, 7.9), (5, 7.6), (5.5, 7.8), (6, 7.2), (7, 6.9). The committee wants an infographic for the school hallway that helps students think about screen time and sleep.
| Category | Level 1 | Level 2 | Level 3 | Level 4 |
|---|---|---|---|---|
| Knowledge and Understanding | Graphs and calculations have many errors. | Graphs and calculations have several errors. | Graphs and calculations are mostly accurate. | Graphs and calculations are accurate and complete. |
| Thinking | Describes the relationship and its limits with little reasoning. | Describes the relationship and its limits with some reasoning. | Describes the relationship, prediction and limits with clear reasoning. | Analyses the relationship insightfully, including hidden variables and the range of the data. |
| Communication | Infographic is unclear; labels, title or source missing. | Infographic is somewhat clear; some labels missing. | Infographic is clear, labelled and has one main message. | Infographic is clear, honest, well designed and convincing. |
| Application | Connects the data to students' lives with limited effectiveness. | Connects the data to students' lives with some effectiveness. | Uses the data to make a sensible message for students. | Uses the data to make a thoughtful, well-supported message for students. |
Lessons in this unit
- One-variable and two-variable dataLearning to tell when a question needs one-variable data and when it needs two-variable data.D1.1
- Collecting continuous dataLearning to collect continuous two-variable data and organize it in a table of values.D1.2
- Scatter plotsLearning to create and read scatter plots.D1.3
- Choosing the best graphLearning to choose the graph that best shows a set of data.D1.3
- Describing relationships and lines of best fitLearning to describe relationships between two variables and to use a line of best fit to make predictions.D1.5
- Misleading graphsLearning to recognize graphs that mislead and to redraw them honestly.D1.6
- Questioning conclusionsLearning to ask good questions about data and to tell the difference between a relationship and a cause.D1.6
- What makes a good infographicWe are learning what makes an infographic clear, honest and convincing.D1.4
- Theoretical and experimental probabilityLearning to compare theoretical and experimental probability.D2.1
- Venn diagrams and tree diagramsLearning to use Venn diagrams and tree diagrams to solve probability problems.D2.1
Ontario curriculum expectations covered
- D1.1
- Tell the difference between one-variable and two-variable data, and explain when each is needed.
- D1.2
- Gather continuous two-variable data to answer a question and organize it in a table of values.
- D1.3
- Choose the best graph for a data set, including scatter plots, and draw it with a title, labels and a source.
- D1.4
- Design an infographic that tells the story of a data set with tables, scatter plots and other helpful features.
- D1.5
- Describe two-variable relationships as strong, weak or none, and positive or negative, with and without a line of best fit.
- D1.6
- Analyse data shown in different ways, spot misleading graphs, question assumptions, and make convincing arguments.
- D2.1
- Solve probability problems with tools such as Venn diagrams and tree diagrams.
- A1
- Every lesson builds in the strand A skills: problem solving, reasoning, communicating, representing, and coping with challenges.
Questions about this unit
How long is this unit?
16 school days: 10 lessons plus a diagnostic, a catch-up day, a two-day performance task, a review day and the unit test.
Which expectations does it cover?
D1.1, D1.2, D1.3, D1.4, D1.5, D1.6, D2.1 from Mathematics (2020), Strand D: Data.
What format are the files?
Each unit comes as a Teacher Guide and Student Pages, both as editable Word files and print-ready PDFs. The Word files open in Google Docs, so you can change anything.
Can I share it with my colleagues?
A single licence is for one teacher's classes. For a grade team, the team licence covers up to 5 teachers at one school for $49.99.
What if it isn't right for my class?
Email help@unitplans.ca within 7 days of buying for a full refund.