This study aimed to: (1) describe the teachers' level of understanding of Domestic Activity Daily Living (DADL) learning for students with ID; (2) describe the activities that the teachers possibly performed, especially in systematic instructions (SI); and (3) the teachers' level of understanding of integrating functional academics in DADL. The quantitative descriptive method is the main method with a qualitative explanation. Interview instruments were used to explore teachers' understanding of DADL. The data analysis used the percentage of the teacher's response frequency, while the qualitative explanation used tags. This research reveals that teachers understand activities to determine learning objectives, but still do not understand activities to provide feedback. The teacher fully understands the gradual learning behaviour as a characteristic of SI. However, teachers do not yet understand how to integrate functional academics in DADL learning for students with ID using a description of the steps in a systematic instruction strategy and other forms of learning manners.