CK-12 is an app to help students, and teachers improve K-12 learning globally by providing self-pace learning content & tools.

Learn over 5,000 math and science concepts at your own pace and in your own style! (videos, assessments, interactive objects, etc)

  • Math subjects include: Arithmetic, Measurement, Algebra, Geometry, Probability, Statistics, Trigonometry, Analysis, and Calculus
  • Science subjects include: Earth Science, Life Science, Physical Science, Biology, Chemistry, and Physics
  • Other subjects include: SAT Exam Prep., Engineering, Technology, Astronomy, English, and History


  • Access Common Core and State Standards aligned content (digital textbooks and concepts).
  • Browse, learn and practice (or teach) over 5000+ concepts using multiple modalities (text, videos, quizzes, flashcards and more).
  • Manage your class online through groups.
  • Assign practice to students and track their progress.
  • Everything on our app and website is always 100% Free.

About CK-12:

CK-12 is a non-profit that creates and curates high quality STEM content for students and teachers around the world. The organization was founded with the mission to enable everyone to learn in his or her own way – for free.

Access the full CK-12 website at

Connect with us:

  • Google +:
  • Twitter:
  • Facebook:


Plan Price Details
CK-12 Free Free for use.


September 2, 2015

CK-12 is a great app for both teachers and educators. It can help students stay engaged and interested, and provide teachers with the tools they need to be effective. With everything online, it is streamlined and efficient.

August 31, 2012

This site a free online flexible textbook for various subjects. The textbooks are aligned with the curriculum standards of various states. The content of the textbooks can be moved around in order to meet the needs of the teacher.