This study aims to: i) model the mathematical abilities trajectories of Canadian children from 7 to 15 years and ii) identify risk factors during early childhood for low math skills trajectories. Using a group-based trajectory approach, we identify three groups of children with distinct mathematical abilities trajectories: average abilities (47.6%), high abilities (30.1%), and low abilities (22.3%). The differences between the groups are increasing over time, especially in early adolescence. Multivariate logistic regressions indicate that the children at risk are those who have a mother with a low level of education, low cognitive score at age 4-5, and have parents with poor parenting skills.