Author note — to cover

Construct ordered stem-and-leaf diagrams with a key, and read individual values, counts above a threshold, mode, median and range straight from the leaves. Discrete or continuous data with exact values kept. Two-sample versions are the sibling back-to-back page; the averages themselves are taught on Averages and spread. Both tiers. (S4)

• Fluency — direct questions on stem-and-leaf diagrams, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).