CK-12 FlexBook 2.0 vs OpenStax

CK-12 FlexBook 2.0 provides customizable digital textbooks for K–12 subjects including science, math, and social studies. Lessons can combine text with PLIX interactives, simulations, adaptive practice, and related learning materials. Adaptive Practice draws questions from a library of more than 150,000 and adjusts selections based on student answers. Teachers can assign lessons, videos, interactives, and practice to whole classes or differentiated groups, then view progress reports. Educators can reorder chapters and edit or add content in customized FlexBooks. The service works in browsers on laptops, desktops, Chromebooks, tablets, and mobile devices, and is listed at free. Standalone Simulations and PLIX Interactives require a tablet-size screen or larger. Users may download PDFs of FlexBooks they create or customize, though interactive content may not render; CK-12-created PDFs are not downloadable. CK-12 says it is still converting all core content to FlexBook 2.0. Listed SSO or LMS partners include Google Classroom, Canvas, Schoology, Kiddom, Clever, and ClassLink.

OpenStax is a nonprofit education initiative of Rice University that publishes free, openly licensed textbooks and related materials for introductory courses. Subject matter experts write the textbooks, which are peer-reviewed for accuracy and updated regularly. Books can be read online on the web, Android or iOS, or downloaded as free PDFs; low-cost print editions are also offered. Most titles are accessible without an account, although a small number require sign-in. Students can highlight, take notes and create study guides, with a free student account required for some features. Educators with a free account can access test banks, PowerPoint slides, solutions manuals and customization tools. OpenStax Assignable lets instructors assign readings, assessments and supporting materials through an LMS, with automatic grading and gradebook synchronization. It supports LTI 1.3 and Blackboard, Canvas, D2L Brightspace and Moodle. Textbooks cost nothing. Assignable starts at $15, paid once, billed per student per semester; instructors use it free, and a two-week trial begins on the first day of access. Institutional pricing is by contact.