Author note — to cover

Find a drawn line's equation: intercept from the y-axis crossing, gradient from a whole-square triangle, then write y = mx + c; include negative and fractional gradients and scales where one square is not one unit. Lines given as coordinate pairs without a picture sit on line-through-two-points. Both tiers. (A9, A10)

• Fluency — direct questions on reading an equation off a graph, 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).