Author note — to cover

Listing every factor of numbers to about 100 in ordered pairs so none is missed; factor and divisor vocabulary; square numbers having an odd factor count. Divisibility tests live on multiples-and-divisibility; counting factors from indices lives on counting-factors. Both tiers. (N4)

• Fluency — direct questions on factors and factor pairs, 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).