One project that focuses on helping students learn science by doing science, and developing a scientist's approach and mindset to solving problems and answering questions about how the natural world works, is what we call the SEE SAW Project. This was developed to help students in Sierra Leone, one of the poorest nations on earth and whose schools do not generally have equipment, supplies, or in many cases electricity (making access to the Internet impossible) start learning STEM differently - moving away from the traditional ways of memorization and reading about things with no active learning of science towards a hands-on, active, and experimentally based way of learning. To actually begin doing science.
The lessons and activities my high school students develop create legitimate STEM lessons and labs/demos that teachers in Sierra Leone use with their students and colleagues. These use the most basic materials and supplies that schools in rural and poor areas can have access to (such as string, rubber bands, water, sand and dirt, rulers, paper, simple timers, containers), in order for students to begin experimentation and observation, and learning to use physical evidence to reach and support conclusions. It turns out that these same lessons and activities can be used by elementary schools in the US. Many schools do not have STEM rooms or labs, and very little equipment or supplies for science and math. Or these can simply be used by elementary teachers who may have limited science experience to develop some good, hands on lessons for teaching science principles.
Anyone is free to use anything on the site. For elementary students, these can be used to get them taking the role of scientist or engineer, and develop a sense for science is really done. Perhaps teachers and students can use the existing lessons to creatively develop their own to investigate different phenomena of students' interests and curiosities!