The study investigates the knowledge profiles of elementary pre-service teachers (PST) concerning numbers and operations before their professional classroom practice. By validating an instrument through exploratory and confirmatory factor analyses, it identifies and categorizes the PST' performance into distinct profiles based on the mathematical knowledge for teaching model. The results reveal that PST demonstrate varying levels of content and pedagogical knowledge. Those with high pedagogical knowledge effectively anticipate student difficulties and employ suitable teaching strategies. In contrast, future teachers with intermediate knowledge can identify errors and explain basic concepts but struggle with advanced strategies. Elementary PST with low pedagogical knowledge face significant challenges in anticipating learning issues and lack effective teaching methods. The study emphasizes the necessity for personalized teacher training to ensure comprehensive and specialized mathematical knowledge that aligns with professional standards, crucial for improving educational outcomes in mathematics.