Author note — to cover

Change the subject when it sits inside a square, square root or denominator, e.g. v² = u² + 2as for u, undoing the outermost layer first; take the positive root unless context demands otherwise. The subject appearing twice is the Higher sibling; substituting values is the substitution group. Both tiers. (A5)

• Fluency — direct questions on rearranging with squares and roots, 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).