Author note — to cover

Cover density as mass per unit volume, rearranged for any quantity, units g/cm3 and kg/m3 with consistency checks, volumes either given or found from Geometry's mensuration formulas. Single materials only here; combining materials is density-of-a-mixture, and rewriting a density in other units belongs to converting-rates. Both tiers. (R11)

• Fluency — direct questions on density, mass and volume, 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).