Math achievement is not a unidimensional construct but includes different skills that require different cognitive abilities. The focus of this study was to examine associations between a number of cognitive abilities and three domains of math skills (knowing, applying and problem solving) simultaneously in a multivariate framework. Participants were 723 third-grade children (mean age = 9.07) from 28 elementary schools. Confirmatory factor analyses with binary indicators showed that a four-factor model of math skills (Knowing-Recalling, Knowing-Computing, Applying and Problem Solving) and a nine-factor model of cognitive abilities (Nonverbal and Verbal Reasoning, Verbal Concepts, Planning, Visuo-Spatial Working Memory (WM), two types of Verbal WM, Phonological Awareness and Phonological WM) fit the data well. Results from structural equation modelling showed that verbal reasoning and verbal concepts were most consistently associated with math knowing and problem solving domains. Verbal concepts contributed also to the math applying domain. In addition, simultaneous processing of verbal WM predicted problem solving skills in math. The results can be used in supporting the learning process of students with difficulties in math. (Contains 2 tables and 2 notes.)