This case study illustrates how a 2nd-grade child, Violet, used an ordinal view of number to reason about positicve and negative integers and arithmetic involving integers. Violet's ordinal view of number facilitated her ability to reason about and correctly solve some integer-related problems and constrained her solutions to others. We demonstrate how Violet's thinking evolved over time while she extended the properties of whole numbers and addition and subtraction to the integers. Using this case study as a basis, we propose a series of developmental milestones that build toward one's understanding of integers and integer arithmetic in an order-based way. We believe that understanding Violet's order-based reasoning can help us listen to other children.
Using order to reason about negative numbers: The case of Violet
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