Data Patterns Revision

Overview

Students revise Year 9 statistical knowledge from Slide 5: reading and creating dot plots and box plots, finding summary statistics, and describing distribution. They apply a clear process to an unfamiliar data set, building from previous work with quartiles, interquartile range and data displays.

Learning intentions

• WALT interpret and compare dot plots and box plots.
• WALT calculate and use the mean, median, mode, range, minimum, maximum, quartiles and interquartile range.
• WALT choose an appropriate statistical display and justify what it shows.
• WALT communicate conclusions using evidence from data.

Success criteria

• I can accurately order data and identify the five-number summary.
• I can construct or complete a dot plot and box plot using a suitable scale.
• I can calculate the IQR and other summary statistics.
• I can describe the centre, spread and shape of a distribution using data evidence.

Curriculum links

• Mathematics and Statistics — statistical investigation, data displays and measures of centre and spread.
• Mathematics and Statistics — interpreting distributions and communicating statistical findings.
• Mathsteasers — higher-order thinking questions that challenge advanced learners and deepen understanding.
• Mathsteasers / Alignment — connected revision that reinforces and extends prior mathematical learning.

Lesson structure (60 minutes)

1. 0–5 min · Retrieval hook. Display Slide 5’s opening question through the retrieval and hook slides: “Two data sets have the same median. Must they have the same spread?” Students write an individual prediction, then compare it with a partner.

2. 5–15 min · Revisit key ideas. Use the summary-statistics teaching slides to review ordering data, mean, median, mode, range, minimum, maximum, lower quartile, upper quartile and IQR. Model the data set 12, 13, 17, 18, 23, 24, 24, 29, 30, 33, 39, explicitly showing that the median is 24 and that the lower and upper halves are used to find the quartiles. Students annotate their own notes and answer short checks on mini-whiteboards.

3. 15–27 min · Teacher model. Show the completed dot plot and box plot on the worked-example slides. Model how the five-number summary becomes a box plot, how the number-line scale is selected, and how a dot plot can reveal clusters, gaps and repeated values. Students identify the minimum, Q1, median, Q3, maximum and IQR, then explain one feature of the distribution to a partner.

4. 27–44 min · Independent revision. Distribute the Year 9 dot-plot and box-plot revision worksheet. Students complete questions involving the provided sibling, screen-time or vehicle-age data: calculate summary statistics, complete a dot plot, construct a box plot, and write a comparison using centre and spread. Encourage students to use the box plot and five-number summary reference mat as a reference while working. Teacher circulates, checking ordered data, quartile method, scales and accurate plotting.

5. 44–53 min · Collaborative error analysis. Display the two deliberately flawed examples from the error-analysis and discussion slides. In pairs, students identify and correct errors such as an uneven scale, a misplaced median, an incorrect quartile or a box plot that does not match the data. Pairs must justify each correction using mathematical vocabulary and evidence.

6. 53–60 min · Plenary and assessment. Use the exit-question and reflection slides to review the opening question. Students complete the final worksheet question independently: “A data set has Q1 = 8 and Q3 = 17. Find the IQR and explain what it represents.” They then state one feature they can identify confidently and one step they will check next time.

Resources

• the complete revision slide deck
• the Year 9 dot-plot and box-plot revision worksheet
• the box plot and five-number summary reference mat
• Mini-whiteboards, pens and erasers
• Calculators, if routinely used by the class
• Rulers and pencils
• Projector or interactive display

Assessment

• Check mini-whiteboard responses for correct definitions, ordering and calculation of the median and IQR.
• During worksheet completion, question students about their quartile method, graph scale and interpretation of centre and spread.
• Collect or photograph the final worksheet response. Look for accurate IQR calculation and an explanation referring to the middle 50% of the data.

Differentiation

• Support learners with a partially completed ordered data set, highlighted median position, a number-line scale and the reference mat. Provide step-by-step prompts: “Order the data”, “Find the median”, “Split the halves”, “Find Q1 and Q3”.
• Offer dyslexia-friendly copies of the worksheet and slides: clear sans-serif font, generous spacing, limited text per line, high contrast and no unnecessary decorative background. Read instructions aloud and allow students to explain conclusions orally before writing.
• For EAL learners, display and rehearse: centre, spread, cluster, gap, minimum, maximum, quartile and IQR. Provide sentence starters such as “The median is ___, so…” and “The IQR is ___, meaning…”.
• Pair students strategically for error analysis, while allowing independent thinking time before discussion. Provide calculator access where calculation fluency is a barrier, without removing the requirement to interpret the display.

Extension

• Students create two different data sets with the same median but different IQRs, then construct displays and explain how the distributions differ.
• Students write a “Which data set is more consistent?” question using two box plots and provide a fully justified answer.
• Advanced learners investigate whether the mean or median is more useful for a chosen data set and defend their decision with reference to outliers or skew.