Myths about teaching can hold you back
- Year 11•
- Higher
- Year 11•
- Higher
Interquartile range
I can calculate the IQR and interpret what this means.
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Lesson details
Key learning points
- The interquartile range tells us how spread out the middle 50% of the data is
- This can be seen visually with a box plot
- Box plots and cumulative frequency graphs can be compared
- This comparison involves the median and interquartile range
Keywords
Interquartile range - Interquartile range is calculated by finding Q3 − Q1. This is because it is the range from the first to the third quartile.
Common misconception
Not referring to the context of the question when comparing the data.
Highlight that just saying the median or the interquartile is bigger is of little use unless you know what the data was about.
To help you plan your year 11 maths lesson on: Interquartile range, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 maths lesson on: Interquartile range, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 maths lessons from the Graphical representations of data: cumulative frequency and histograms unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Prior knowledge starter quiz
6 Questions
Q1.Anything below the __________ represents 75% of the data.
Q2.Anything below the lower quartile represents what percentage of the data?
Q3.What is the range of the middle 50% of data?

Q4.A wider box indicates data that is consistent.
Q5.Which class did better on average?

Q6.Which class' scores were more consistent?

Assessment exit quiz
6 Questions
Q1.Which of the following describe the interquartile range?
Q2.What is the interquartile range of the data represented on this box plot?

Q3.Calculate the interquartile range from this cumulative frequency graph.

Q4.What is the interquartile range of this set of data? 17, 13, 19, 21, 13, 14.
Q5.This table shows information about the heights of some year 7 and 11 pupils. Compare their heights by selecting the most useful statement.

Q6.This table shows information about the times some children and adults take to complete a puzzle. Compare their times by selecting the most useful statement.
