Integration of computational thinking (CT) into numerous disciplines across the K-12 curriculum is gaining increased attention. In this study, based on the technology integration framework, we investigated how students’ understandings, difficulties, and attitudes towards learning subject matter varied at different levels of CT integration. We implemented six different case studies by integrating CT into six different subjects: science, traffic, language, biology, geography, and physics. Two primary and four secondary school teachers, 38 primary school students, and 113 secondary school students were involved in the study. We categorized these lessons according to the technology integration model: unplugged activities are grouped as augmentation level; robotic and two modeling activities are labeled as modification level; modeling and digital storytelling activities are labeled as redefinition level. Our findings indicate that students reported a very positive attitude toward redefinition level activities. Teachers stated that compared to standard instructional activities, students can go deeper and understand the subject content better in CT integrated lessons.