Author note — to cover

Translate two facts about two unknowns — tickets and totals, sums and differences, mixed baskets of prices — into a pair of linear equations, solve by either method, and interpret both values in context with units. Pure technique lives on the elimination and substitution siblings. Both tiers. (A19, A21)

• Fluency — direct questions on forming simultaneous equations from a problem, 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).