This research presents two case studies on how human-centered design process can help the students find their purpose in making and designing in a constructionist learning-environment. Human-centered design guides students to deeper understanding of others' needs and encourages them to think and act collaboratively and creatively. When the students are making prototypes, they are creating objects-to-think-with, which enables them to express themselves, learn, explore and experiment with new knowledge and boundaries. The research is implemented through the Little Builders program, a month long four-day program in Bangkok, Thailand. Its design builds upon the constructionist framework with the support of human-centered design process, providing 8th grade students in a Thai urban school the opportunity to design and build social innovations as a team in an after school setting.