Dimensionality of preschoolers’ informal mathematical abilities

•Dimensionality of informal mathematical abilities for preschoolers is identified.•The confirmatory factor analysis includes 35 items of the Child Math Assessment.•The model includes Number and Operations, Measurement, Geometry, and Patterning.•The factor – Number and Operations explains common variance in Number, Operations, and Relations.•There are no differences for males and females for the four factors or 35 items.