The present study investigated the extent to which verbal intelligence (VIQ) and performance intelligence (PIQ) contribute to strategy selection and execution in the context of a numerosity judgement task. The choice/no-choice method was used to appropriately assess strategy selection (in terms of strategy repertoire, frequency and adaptivity) and strategy execution (in terms of strategy speed and accuracy) in a group of 120 12-year-old children. For each parameter, a regression analysis was carried out with VIQ and PIQ, as independent variables, and with arithmetic proficiency as a control variable. Results showed that VIQ was a significant predictor for all parameters of strategic competence, whereas PIQ only explained a unique portion of the variance above and beyond VIQ in the speed of strategy execution. (Contains 3 tables and 2 figures.)