CK-12 is divided into three sections: Mathematics, Science, and More. Mathematics includes subjects from arithmetic to trigonometry and statistics. Science covers all the bases: biology, chemistry, and physics, as well as life, earth, and physical sciences. The More section offers history, technology, and economics. Within each subject, you can click on a circle to get even more specific; each contains a number of Concepts, which are short, chapter-like lessons. For example, if you click on \"phases of matter\" within the physical science section, you will be given a list of topics that include evaporation, sublimation, and solutions. Within those, you can choose from a series of modalities: read, study aids, video, or web links.
You can bookmark material you'd like to save for later, or you can send it to a classmate by email or social media. Kids can create groups to share content with each other. If you're looking for a very specific topic, enter it into the search box to go straight there.