Author note — to cover

Find the equation of the line through two given points: gradient from the coordinate differences first, then c from either point, checking with the unused one; include negative and fractional answers. Midpoints of the same segment belong to the coordinates group. Both tiers. (A9)

• Fluency — direct questions on the line through two points, 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).