Math lesson plan · 8th grade (Year 9 in England) · 30 minutes
Spot outliers and clusters in scatter plots
Statistics and probability
CCSS 8.SP.A.1England: KS3 StatisticsEngland: GCSE Foundation Statistics
Objective and success criteria
Students will: Spot outliers and clusters in scatter plots.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Describe association in scatter plots
Leads to: the next skill in this area.
Materials: Squared paper for charts, Class survey data, Sticky notes for a live chart, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Describe association in scatter plots). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What association would you expect between: Outside temperature and heating bill? (Positive / Negative / None) → NegativePrompt: Imagine one quantity increasing. What tends to happen to the other?
- What association would you expect between: Height of a tree and the length of its shadow at noon? (Positive / Negative / None) → PositivePrompt: Imagine one quantity increasing. What tends to happen to the other?
- What association would you expect between: Age of a car and its resale value? (Positive / Negative / None) → NegativePrompt: Imagine one quantity increasing. What tends to happen to the other?
Hook · 3 min
- Take a quick class survey (favorite fruit, travel to school) and ask what the results tell us.
- Share the objective: Spot outliers and clusters in scatter plots. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Model one question from the student sheet, thinking aloud.
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
You do: independent practice · 7 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 2 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
Watch out for
- Forgetting to put data in order before finding the median.
- Reading a bar's height wrongly when the scale goes up in 2s or 5s.
Support and stretch
Support
- Review first: Describe association in scatter plots.
- Use concrete materials: squared paper for charts.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-8.
Free lesson plan from eurekami.com/lesson-plan-builder