Indicator 3a

The materials show a clear, intentional design distinguishing problems (where students learn new mathematics) from exercises (where they apply learning to build mastery): Concept Development segments present problems with explicit purposes (e.g., [E4]/[E9] 'Problem 1: Assess sample student work for accuracy and efficiency'; [E11] 'Problem 2: Assess peer work'), while Problem Sets have students apply strategies to build mastery ([E6], [E8]). Each problem carries a stated purpose—the teacher-edition 'Note:' annotations explain why each problem is included ([E7] 'Problem 3 is challenging because...', 'good contrast between comparison and put-together problem types'). The teaching sequence is explicitly framed 'Toward Mastery' with sequenced objectives ([E12]), and [E6] confirms intentional design choices ('Some problems do not specify a method... This is an intentional...'). This structural evidence supports all required components.