Need a quick and easy shortcut to set a scale in a viewport? Use the View Scale PostalCAD tool. 

Simply enter VSC for View SCale at the command line when you are in a layout tab.  A pop-up list appears at the tip of your cursor with the most common architectural scales.  Just choose the one you need and if this doesn't work, pick the next scale up or down to correct the sizing.  There is also a User Input listing at the bottom of the list which prompts you to set the scale manually.

To see what scale a viewport is scaled to, open the properties box with the viewport highlighted.  Next look in the Misc area for the Standard Scale edit box.  You can also open the Viewports toolbar and enter model space mode of any viewport to see the current scaling.