This article aims to develop an instructional design in applying the Jigsaw cooperative learning model to the ability to understand mathematical concepts and the self-efficacy of students at SMK N 26 Pembangunan Jakarta. The learning material chosen is lines and series, covering the following sub-topics: Arithmetic series, geometric series, arithmetic series, and geometric series. The steps before forming the instructional design carried out a needs analysis in which classroom observations and teacher and student interviews were carried out. After the needs analysis is obtained, a learning plan is formed that will be created and will be implemented in the next lesson.
