There are many different ways to leave feedback on student assignments in Class Notebook.
Leave written feedback
Record and embed audio feedback
Record and embed video feedback
Go to the student’s assignment and make a video recording with OneNote 2016. Your student can watch the video from the same page.
Go to the area of the page where you want to leave feedback. Select Insert, then Stickers. Select your sticker, customize the caption (optional), and select Submit.