Concept:Learning a mathematical concept like 'half' must follow a sequence from concrete experiences to abstract symbols: hands-on activity, then language, then pictures, and finally symbols.Explanation:The teacher should first let students physically divide objects into two equal parts (C). Next, use words or a story to label that idea as 'half' (D). Then show pictures representing 'half' to connect the concept to visuals (A). Finally, introduce the written symbol for 'half' (B). This concrete-to-abstract order (E-L-P-S model) builds understanding step by step.Answer:B. C, D, A, B