Children's arithmetic performance is dependent on the arithmetic task format, but little is known about how domain-specific and domain-general abilities contribute to solving diverse arithmetic problems. In this study, 145 Italian typically developing children between the ages of five and six, who have not yet received formal schooling, were administered the same addition problems in diverse formats (nonverbal problems, story problems, number-fact problems), diverse number-knowledge tasks (set comparison, number sequence, set to numerals, and count principle tasks), and domain-general tasks (fluid intelligence, language, visuoconstructive skills, working memory, and inhibition tasks). Results indicated that children were more accurate on nonverbal problems, followed by story problems and number-fact problems. Furthermore, performance on diverse problems was differently associated with the other variables, which suggests that different problem formats draw on different cognitive skills.