I insist my students learn how to use a Real E6B, so they can understand and visualize wind effects. The back side is the easiest way to get Density Altitude and TAS, and the use of those functions is required for some test questions. Are you sure the examiner won't want to see a navigation log as part of the oral?
Finally, 61.105 requires it:
§ 61.105 Aeronautical knowledge.(a)General. A person who is applying for a private pilot certificate must receive and log ground training from an authorized instructor or complete a home-study course on the aeronautical knowledge areas of paragraph (b) of this section that apply to the aircraft category and class rating sought.
(b)Aeronautical knowledge areas.
(4) Use of aeronautical charts for VFR navigation using pilotage, dead reckoning, and navigation systems;