Until about 130 years ago, there was a fourth "R" in the basics firmament - rhetoric. It virtually disappeared after the advent of universal elementary education, not because it was deemed unimportant, but because classes were too big for teachers to allow children to speak at length.
The exception is the private sector, where public speaking remains on the curriculum, helping young people not only to feel self-confident, but also to sound competent.
So let us praise Edmund Waller primary in the London borough of Lewisham (page 5), whose 445 ethnically-diverse pupils learn from the age of five to speak comfortably in front of an audience. Schools like this know that good speaking and good writing go hand in hand. Literate talk will also become more important as voice recognition software takes over from keyboards. But above all, it helps to bridge the class divide.