Math lesson plan · 9th grade (Year 10 in England) · 45 minutes
Averages from frequency tables
Statistics and probability
CCSS HSS.ID.A.2England: GCSE Foundation StatisticsEngland: GCSE Higher Statistics
Objective and success criteria
Students will: Averages from frequency tables.
- 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: Mean, median, mode and range
Leads to: Histograms and grouped data
Materials: Squared paper for charts, Class survey data, Sticky notes for a live chart, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Mean, median, mode and range). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Find the mean of: 11, 8, 7, 4, 5 → 7Prompt: Add all the numbers.
- Find the median of: 23, 8, 28, 3, 1 → 8Prompt: Put the numbers in order first.
- Find the range of: 11, 7, 9, 10, 16, 11 → 9Prompt: Range = largest − smallest.
Hook · 5 min
- Take a quick class survey (favorite fruit, travel to school) and ask what the results tell us.
- Share the objective: Averages from frequency tables. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: The table shows the number of pets per household: 0 pets: 9, 1 pets: 5, 2 pets: 5, 3 pets: 3, 4 pets: 6. Find the mean number of pets. Round to 2 decimal places.
- Step 1: Σfx = 0×9 + 1×5 + 2×5 + 3×3 + 4×6 = 48
- Step 2: Σf = 28
- Step 3: 48 ÷ 28 ≈ 1.71
- Answer: 1.71
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- The table shows the number of pets per household: 0 pets: 3, 1 pets: 3, 2 pets: 7, 3 pets: 3, 4 pets: 9. Find the mean number of pets. Round to 2 decimal places. → 2.48Prompt: Multiply each value by its frequency and add.
- Shoe-shop sales by size: size 4: 1, size 5: 1, size 6: 8, size 7: 4, size 8: 1. What is the modal shoe size? → 6Prompt: The mode has the highest frequency.
You do: independent practice · 10 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 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- The table shows the number of pets per household: 0 pets: 2, 1 pets: 5, 2 pets: 8, 3 pets: 4, 4 pets: 7. Find the mean number of pets. Round to 2 decimal places. → 2.35Prompt: Multiply each value by its frequency and add.
- Shoe-shop sales by size: size 4: 3, size 5: 3, size 6: 1, size 7: 1, size 8: 7. What is the modal shoe size? → 8Prompt: The mode has the highest frequency.
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: Mean, median, mode and range.
- 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
- Move on to: Histograms and grouped data.
- 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-9.
Free lesson plan from eurekami.com/lesson-plan-builder