The Plan: Zoom In command is found on the View menu. Unlike the Zoom In tool in the editor toolbar, this zooms in from the center of the current view and does not require a screen-pick. It zooms at small increments.
You can also invoke this command from the keyboard by pressing the [Ctrl][Shift][=] to zoom and center your plan. Or use [Ctrl][+] combination to just zoom in.
Note: Use the Zoom in tool to zoom and pan (scroll) simultaneously.
Click HERE to learn about there zoom commands.