||A review of traditional mathematics instruction suggests that conventional methods emphasize student learning of declarative rules about math problem solving procedures, especially in the early phase of learning. In contrast to the implicit learning of procedural skills, this approach places heavy demands on working memory and may be partly responsible for low levels of math achievement by many students. The present study explored the plausibility of implicit learning of polynomial problem structure prior to declarative rule instruction and its impact on subsequent problem solving skill, rule learning, and perception of difficulty. Participants selected proper factorizations of quadratic polynomials from two possible answer choices over many blocks in a task that was structured to achieve errorless learning through a vanishing cues approach. Measures were administered to assess problem solving skill, rule understanding, and perception of learning difficulty. Evidence supports the hypothesis that some mathematics skill can be learned implicitly, but marginal and conflicting results raise questions about the impact of initial implicit learning on subsequent rule learning and difficulty perception. Findings are interpreted with respect to implicit learning and skill acquisition theories.