Quartiles and Interquartile Range | I Do, We Do, You Do | Year 10 Maths Higher | Print Free

Calculate quartiles and develop deeper reasoning about data with this editable Year 10 Maths Higher lesson. Pupils calculate the lower quartile, median, upper quartile and interquartile range, work backwards from given summaries, and construct data sets that satisfy several conditions.

WHAT IS INCLUDED
• One editable 71-slide PowerPoint with answers.
• Six retrieval questions and six prerequisite questions, with grouped answers.
• Definitions of median, quartiles, interquartile range and range.
• Two I Do / We Do modelling pages with six matched pairs and worked solutions.
• Twenty individual AFL questions, each followed immediately by its answer.
• Thirty-six whole-class practice questions on one page, followed by one grouped answer page.
• One differentiated page containing twelve Developing, five Secure and four Greater Depth questions, plus a clearly separated Super Challenge.
• Grouped differentiated answers and two challenge solution pages.
• Four misconception checks with explanations.
• An original six-mark exam-style question with suggested marking points.
• Three exit-ticket questions, each followed by its answer.

MODELLING WITH A CLEAR METHOD
Pupils order the data and use the medians of the lower and upper halves. For an odd number of values, the lesson explicitly excludes the overall median from both halves. Matched I Do / We Do examples use different data, allowing the teacher to model a method before pupils try a related question. The second modelling page covers missing values, changes to every score and constructing a valid data set.

SUBSTANTIAL PRACTICE ON ONE SCREEN
Three columns provide ordered lists, different list lengths, and unordered data including negative values, decimals and repeats. Pupils calculate four measures for every list. Answers appear together in a stated order for efficient checking.

DIFFERENTIATION THAT ADDS DEPTH
Developing consolidates calculations with fresh data. Secure includes missing values, transformations of data and comparisons of journey-time spread. Greater Depth asks pupils to disprove a claim, find every possible pair of missing whole-number values, construct contrasting data sets and explain why changing an extreme score can leave the IQR unchanged.

A SUPER CHALLENGE BUILT AROUND PROOF
Pupils construct eight-score data sets with a fixed minimum, maximum, median and IQR, but different lower quartiles. They then find every possible whole-number lower quartile and prove their list is complete. Worked solutions show both the necessary limits and a construction that makes every candidate possible.

PRINT FREE AND FLEXIBLE
Project the questions while pupils work in exercise books or on mini whiteboards. No printed worksheets are needed. Keep the whole class active on one differentiated slide, reveal answers when useful and adapt the editable PowerPoint to suit your class.