Author note — to cover

Leave circle answers as exact multiples of pi, add and subtract such multiples unrounded, and give exact or rounded answers as the question demands. Exact calculation with multiples of pi is the Number strand's N8; here it meets circles, arcs, sectors and cylinder volumes. Both tiers. (G17, N8)

• Fluency — direct questions on answers in terms of π, 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).