Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Find the median of an even-sized data set
Statistics and probability
CCSS 6.SP.B.5.CEngland: KS3 StatisticsEngland: GCSE Foundation Statistics
Objective and success criteria
Students will: Find the median of an even-sized data set.
- 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: Find quartiles and the interquartile range; Choose the best average and see how outliers affect it
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, 11, 12, 15, 12, 11 → 12Prompt: Add all the numbers.
- Find the median of: 17, 26, 26, 12, 7 → 17Prompt: Put the numbers in order first.
- Find the range of: 7, 1, 1, 6, 14, 1 → 13Prompt: 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: Find the median of an even-sized data set. 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: Find the median: 18, 40, 34, 28, 3, 21
- Step 1: 3, 18, 21, 28, 34, 40
- Step 2: (21 + 28) ÷ 2 = 24.5
- Answer: 24.5
- 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.
- Find the median: 19, 16, 28, 20, 36, 6, 27, 25 → 22.5Prompt: Put the values in order first.
- Ten students recorded text messages sent in a day: 46, 44, 20, 46, 52, 14, 45, 25, 32, 54. What is the median? → 44.5Prompt: Order the 10 values.
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.
- Find the median: 30, 2, 7, 38, 11, 23 → 17Prompt: Put the values in order first.
- Ten students recorded daily high temperatures (°C): 22, 25, 29, 26, 16, 28, 28, 14, 23, 9. What is the median? → 24Prompt: Order the 10 values.
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: Find quartiles and the interquartile range; Choose the best average and see how outliers affect it.
- 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-6.
Free lesson plan from eurekami.com/lesson-plan-builder