Building and using molecular models puts into action chemical language and concepts, as well as concepts from other disciplines, such as mathematics. It is an important didactic activity for understanding and exchanging meanings about fundamental concepts in basic and advanced chemistry topics. The models described here help students understand molecular representation, which is abstract and difficult to imagine and draw, and then integrate it with chemical situations and knowledge. On the basis of our experience with students, particularly in a class of 44 students, inviting them to build their own molecular models is an activity that promotes their participation in class and the laboratory. We provide details regarding how to use inexpensive plastic drinking straws for assembly; they cost very little and enable analogue models that express connectivity in molecular structures to be built, a strategy that enhances understanding of the spatial organization and characteristics of molecules, as well as that of molecular thought for solving chemical problems.