Reading, writing, and arithmetic (i.e. mathematics). They're considered the three fundamentals everyone should learn by the time they finish elementary education... well hopefully.

Yes, only one of the Three R's actually starts with the letter 'r'. The phrase originally started as a joke, but today it's more of an idiom.
It's a terrible school; the children are not even taught the three R's.
by Willow weep for me February 14, 2008
Get the Three R's mug.
Rich
Revenge
Racist
these are the three r's of eric cartman. things related to eric cartman. that start with r.
Kyle- Wow, Cartman is always coming up with some stupid idea to be racist, get rich, or get revenge.
Kenny- Yeah!

Stan- Those all start with R.
Kenny- The Three R's of Eric Cartman. *chuckle*
by yhjdfhjg June 11, 2023
Get the The Three R's of Eric Cartman mug.
The three r’s is Ranboo Rock Roller
It is a motivational quote to live by
“Hey, What’s the three r’s?”
“It’s Ranboo Rock Roller! A motivational quote to live by”
“Thanks man, i’ll live by that”
by June 29, 2021
Get the The three r’s mug.