This research adopts a mixed-methods approach to explore and enhance middle-class students' understanding of complex numbers. The study delves into the relationships, applications and real-life contexts of complex numbers, considering their relevance in algebra and trigonometry. The primary objective is to design a didactic sequence enabling tenth-grade students to develop a comprehensive and geometric perspective of complex numbers, including operations, transformations, and practical applications in problem-solving and real-world situations. The research targets several key objectives. First, it identifies challenges in teaching and learning complex variables within vocational schools. Second, it demonstrates effective didactic approaches and classroom practices to enhance the complex variable instruction. Third, the study constructs a didactic proposal leveraging geometric and analytical concepts previously acquired by students in their earlier courses. Finally, the research integrates an engaging computational element to effectively validate students' learning outcomes. The study employs essential tools: the geoboard, facilitating practical knowledge acquisition, and various software applications such as GeoGebra, Excel, and the video game "Enigma" to foster student engagement and reinforce learning. This research significantly contributes to mathematics education by presenting a novel and comprehensive didactic proposal for teaching complex numbers. By addressing teaching and learning challenges, it offers valuable insights and effective classroom practices for educators. Moreover, incorporating geometric perspectives and engaging computational elements create a well-rounded and holistic learning experience for students. Ultimately, the study findings can enhance the complex variable instruction in vocational schools, positively impacting mathematics education overall. Keywords: Lateral Number, Geoboard, Didactic Sequence, Didactic Engineering, Complex Number DOI： https://doi.org/10.35741/issn.0258-2724.58.4.52