CK-12 FlexBook 2.0 vs Teach Starter

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.

Teach Starter is a web-based library of teaching resources, classroom tools, and educator apps for K–6 teachers. Its collection covers curriculum-aligned printable and digital worksheets, activities, games, and classroom materials across subjects including English language arts, mathematics, science, social studies, health, fine arts, languages, and social-emotional learning. Resources come in formats such as Google Slides, PowerPoint, PDF, Word, and Google Sheets. With Plus, teachers get editable resources, lesson plans that combine materials with differentiation and assessment guidance, and unit plans that group lessons. Teach Starter Studio supports creating and adapting resources and display materials. The Free plan costs nothing, requires no credit card, and limits downloads to free resources, which are non-editable. Plus costs $6.08 a month, billed $73 yearly. School Plan costs $73 a year per teacher, requires at least five teachers, and includes Plus and one administrator account. Plus resources and digital tools remain available only during the subscription period.