Even without an OrbitNote license, Equatio can be used from within other PDF readers.  Open Equatio, and utilitze the Screenshot Reader functionality.  From a teacher standpoint, this would be a good opportunity to copy problems from a PDF and insert them into a more flexible collaborative space such as a Google Doc.  Once the problems have been read aloud, choose the ‘More Options’ button, and select ‘Copy LaTex.’  Then with your mouse, return to your Google Doc, and select the ‘LaTex Input’ method, and perform a simple ‘CTRL V’ to paste the math into Equatio.  Hit the ‘Insert Math’ button and the problems will go right inside your document.  As a student working from within PDFs, I can utilize Equatio, by hearing the math audio playback of the problems I am being asked to solve or complete.  Keep in mind, you will not see an ‘Insert Math’ button unless you are using OrbitNote, which is Texthelp’s PDF reader tool.