Displaying grid lines in Autodesk Inventor can help you transition from hand drawing to CAD drawings.
When you display Grid lines, they are set to a 1/8″ scale by default. You also have the option to Snap to grid in settings. Snaps occur at 1/16″ increments by default, but you can control this with the toggle at the bottom of your screen.
You can display grid lines by selecting Application Options and then the Sketch tab.