Why can't I copy files between the external & interal SD on an Android 4.2 tablet?

When I insert a micro-SD card into the tablet, I can open the graphical "*file manager*" in the apps and view which files & folders are on the internal-SD and the external-SD. However I can not discover how to copy a file *from* the internal *to* the external SD or vice-versa. The File Manager lets me create a copy of a file in the same folder, but there was no hint given as to how to copy or move a file from one folder or storage medium to another. The tablet I am trying to work with is apparently a FAST-TOUCH (??) which is running Android 4.2.2. I think it may be this 10" tablet , or at least it is very similar to it. I did not purchase the tablet and I definitely do not have "admin" access. I have tried to locate a user manual, but I do not think one exists. It seems to be rather common for Android devices to come with little or no useful documentation. I would normally never bother to ask about this since I always considered simple file ops to be very trivial procedures. But I have never used an Android tablet (or phone) before and, frankly, I do **not** find using it to be as intuitive as I think others assume it to be. **A Note About Edits** ------------------ This question previously focused on asking about documentation. I have stripped most of that out and repurposed the question to ask only about how to do a simple file copy with the File Manager on the tablet. Before I posted the question I attempted to locate previous questions about basic Android documentation, but failed to find them. For some reason, I only seem to be able to find the questions I am looking for if I first create and post a duplicate question. I am posting links to the general documentation questions I found below for possible future reference since, frankly, I doubt my ability to find them again. https://android.meta.stackexchange.com/questions/371/where-can-i-ask-questions-that-arent-android-enthusiast-questions https://android.stackexchange.com/questions/17760/where-can-i-find-a-thorough-introduction-to-android https://android.stackexchange.com/questions/32894/android-jelly-bean-help-or-user-manual