Word document size at open?

When I open Word, on *any* document, the document image fills less than a quarter of my screen. How do I set the default opening size to be more comfortably sized? No, it isn't that last size that was saved. I expand the document to a useful screen size, and resave it. When I open it, the size is still less than a quarter of the screen. Nothing changed. I'm using Word for Mac 16.16.27 (Word 2016).