Author note — to cover

Substitute negative values wrapped in brackets, covering (−3)² versus −3², subtracting a negative, and products of two negatives, in expressions like 2x² − 3x with x = −4. Boundaries: positive-only substitution and formula work sit on the sibling pages; the sign conventions themselves are Number-strand material. Both tiers. (A2)

• Fluency — direct questions on substituting negative numbers, 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).