PheET Interactive Simulations

Founded in 2002 by Nobel Laureate Carl Wieman, the PhET Interactive Simulations project at the University of Colorado Boulder creates free interactive math and science simulations. PhET sims are based on extensive education research and engage students through an intuitive, game-like environment where students learn through exploration and discovery.

Khan Academy

Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. Subjects include math, science, computing, history, art history, economics, and more, including K-14 and test preparation (SAT, Praxis, LSAT) content. The primary focus is on skill mastery to help learners establish strong foundations.


CK-12 is an excellent Open Educational Resource (OER) that is free and easy to use. Digital resources include PLIX interactives and simulations, adaptive practices, study guides, and FlexBook digital textbooks. CK-12 FlexBooks are complete online platforms for assembling, authoring, and distributing standards-aligned, interactive, multi-modal educational content.


eSpark can be used at home for K-5 students to continue to access math and reading content at a level that’s right for them, even if they’re not in the classroom. Learn at home with individualized reading and math activities. Diverse third-party games, videos, and resources help students practice new skills


CK-12 provides free courses in Math and Science (and more) for grades 1-12. Courses are highly engaging for students with real time feedback using interactive content and adaptive practice. It can be assigned by a teacher and used independently by a student.