I advise beginners to ignore videos that advocate playing two notes[fifth apart]with one finger.it is a limiting technique.
I do it occasionally ,but generally prefer to play each note of a chord,and each button with one finger.
you can then play a legato chord without having to remove a finger,example, left hand side C root position chord.
if you use the method I advocate,you can play C, ADD E,then ADD G,holding all the notes on,this is impossible with any other method.http://www.dickmiles.com