How to open multiple tabs using Ctrl + something + number of tabs?

Or anything similar, just one step, for someone who is new to the computer who never opened an email account never subscribed to anything etc.
That is not whatI’m referring to.

That is instead of the usual click click click click, one tab at a time, (eg one for Fluther one for Google one for Bing one for a dictionary, etc.) This is just as an alternative in case that + sign in Firefox and the empty grey square box on Explorer on the right top of the screen, aren’t there, not because the click click click is too time consuming.