If you need to use Khan Academy in an environment without internet, we recommend using Khan Academy Lite: An unofficial volunteer-driven initiative to provide a version of the Khan Academy videos and exercises that works offline.
Khan Academy Lite (or KA Lite) is an open-source software that mimics the online experience of Khan Academy for offline situations. Running KA Lite as a local server, you can watch Khan Academy videos, complete exercises, and track student progress - all without needing an Internet connection!