Author note — to cover

Rearrange forms like 2x + 3y = 6 and x + y = 4 into y = mx + c before reading gradient and intercept, and decide whether pairs of such lines are parallel; name the trap of quoting the unrearranged x coefficient as the gradient. Both tiers. (A9, A10)

• Fluency — direct questions on lines not written as y = mx + c, 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).