Students learn about how body system works. In the beginning, students were asking by teacher to predict what inside human body. From that activity, students were able to mention the organs of human body. As continuation of the previous activity, students tried to recognize main organs of human body. They discussed the main organs by using the case of Nick Vujicic. After that, students arranged some main organs picture and classified it to four main systems: respiratory, skeletal, circulatory and digestive systems. As conclusion, they wrote their understanding related to organs in each system in form of lotus diagram.