We use a couple different open and go curriculums for science and art, but sometimes the kids need a hands project to break the monotony of the books. I recently began using KiwiCo. With this company, you order a specialty kit for your child's age group. Science and tinkering, art and design, and geography and culture. My 6 year old has built a crane and learned about the pulley system. My 10 year old built an arcade catapult using rubber bands and taught him about potential and kinetic energy. Each kit comes with a Tinker Zine book with additional ideas to make using these newly learned lessons.