With the free CK-12 app for iPhone and iPad, you’re in control of learning. CK-12 features 5000+ math, science, and spelling lessons and concepts - all accessible anytime, anywhere. All content is created and curated by teachers, for students. Whether you’re looking to improve your grades, or brush up on your favorite math or science topics, CK-12 has you covered - for free! We’re the go-to resource for K-12 STEM education.

* Practice & Learn at your own pace
* Track and work on your class assignments.
* Receive reminder for upcoming assignment deadlines.
* Choose from a comprehensive library of elementary, middle and high school concepts in math and science, or search by keyword.
* Thousands of math and science quizzes
* Easily track your progress on all subjects
* Improve over time and see your progress with reports
* Get recommendations for learning resources
* Advanced diagnostics and remediation to help students through their practice and assignments
* Videos, simulations, interactives, real world group activities & more!

Topics covered:
- Elementary Math:
* Addition, Subtraction, Multiplication and Division
* Time
* Measurement
* Geometry
* Place Value
* Decimals and Fractions
* Money
* Factors and Multiples
* PEMDAS (Order of Operations)

- Math:
* Arithmetic
* Measurement
* Algebra
* Geometry
* Probability
* Statistics
* Trigonometry
* Analysis
* Calculus

- Science:
* Earth Science
* Life Science
* Physical Science
* Biology
* Chemistry
* Physics

- English
* Spelling

See all of our learning resources, including free digital textbooks, at

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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.

What's New

Version 3.8.0

* Our app now looks awesome on the new iPhone X.
* We have also made a change so that students can turn in their assignment scores for practice and quizzes just like for other assignments.

Ratings and Reviews

2.9 out of 5

16 Ratings

16 Ratings

Skill level does not work!


Had to download this app for school and it's horrible. The skill level does not increase when I get 9 in a row, but of course drastically drops when I get an answer wrong. There have been a couple instances where the class has done an assignment but it will not submit, or the teacher cannot access out scores.

Developer Response

Sorry for the issues you faced in the app. We have fixed the bug that prevented the assignment scores from being reported to the teacher. You can contact us at if you are facing any other issues with the app.

poor controls


trying to go through an exercise and videos tutorials keep popping up.

try and dismiss them, but the hit state is so small that they open instead of going away.

i’m a ux designer and those usability fails really “grind my gears”.

so simple, yet so rarely do developers and product peeps pay attention to BASIC DETAILS.


hey there buddy pal chum

Skills don’t work. Logs me out every time I open. Crashes.

Developer Response

Sorry to hear about the issues you are experiencing. We are not seeing any issues like these during our testing. Please contact us at so we can help you with this problem. Please include the iOS version and the device you installed the app on to help us debug.


CK-12 Foundation
42.4 MB
Requires iOS 7.1 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2017 CK-12 Foundation


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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