CK-12 is a free online resource that offers a variety of tools and materials for teachers and students. Teachers are able to access CK-12 resources, assign work, and grade student submissions in Schoology. Teachers will need to add the application to each of their courses in order to integrate CK-12 materials in their Schoology course.

Installing the CK-12 Application in Schoology Courses. 

1. Go to the Schoology App Center. (There are a lot of apps listed, however many of them are subscription based and requires a purchased license.)

2. Locate and click on the CK-12 application.

3. Click Install LTI 1.1 App.

4. Select Install for Me.

5. Click the box next to each course you want to use CK-12 materials and click Install.

6. CK-12 will be listed on the right side of the Add Materials options.