Children’s strategy use in computational estimation

Abstract This study reports an investigation of ten-year-old children's strategy use in computational estimation (i.e., give an approximate answer like 400 to an arithmetic problem like 224 + 213). Children used four strategies: rounding with decomposition, rounding without decomposition, truncation, and compensation. Strategies appeared to differ in frequency and effectiveness. Finally, children chose strategies in an adaptive way so as to obtain fast and accurate performance. Implications of these findings for understand-ing children's computational estimation performance and strategies in numerical cognition in general are discussed. One of the most fundamental goals of research on early numeracy is to determine how children solve numerical problems. This goal has been pursued in domains of mathe-matical cognition as varied as acquisition of number concept and number names, subitizing and counting, as well as arithmetical problem solving; In all of these domains, researchers have found that children use several strategies to solve numerical problems (see Dehaene, 1997; Geary, 1994, for recent overviews). A much less-documented numerical activity is computational estimation. Computational estimation is defined as finding an approximate answer to arithmetic problems without actually (or before) computing the exact answer (e.g., 23 + 69- 90). It is an important component of mathematical cognition, as it provides information about people's general understanding of mathematical concepts, relationships, and strategies, and about children's cognitive development in the domain o