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| | Developmental Theory |
 | | In this stage (characterized by 7 types of conservation: number, length, liquid, mass, weight, area, volume), intelligence is demonstrated through logical and systematic manipulation of symbols related to concrete objects. |
 | | He noted that a significant percentage (and, an even higher percentage of education majors) were not at the Formal Operations level. |
 | | The levels of the model, in order, are "visualization," "analysis," "informal deduction," "formal deduction," and "rigor." The van Hiele research asserts that students must move through the levels in order, and they must have understanding at each level before moving on to the next. |
| www.uoregon.edu /~moursund/Math/developmental_theory.htm (1140 words) |
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