In Google Classroom select your class, head to the Classwork tab, click the Create button and select Assignment. Choose a title and description. Attach your PDF by clicking the ‘Add Google Drive file’. At this stage, you might want to include some annotation for your students. Click on the PDF and use the ‘Open with OrbitNote’ button to open the document. Make your annotations and comments. When you are ready, click on the small arrow next to the classroom icon in OrbitNote’s toolbar and select ‘Share Annotations with Students’. Close your PDF and click the Assign button in Google Classroom.