Three studies investigated 5- to 8-year-olds' ability to solve partitive division problems when presented with a concrete model of a problem. Children found it easier to solve problems in Grouping-by-Divisor condition than in Grouping-by-Quotient condition, although there was evidence of developmental improvement in tasks. Findings suggest that Grouping-by-Divisor is easier because it coincides with the end point of sharing. (Author/KB)