The three Rs
The three Rs (as in the letter R) refers to the foundations of a basic skills-oriented education program within schools: reading, writing and arithmetic. It appeared in print as a space-filler in "The Lady's Magazine" for 1818, although it is widely quoted as arising from a phrase coined in a toast given by Sir William Curtis, Member of Parliament, in about 1825. Since its original creation, many others have used the term to describe other trifecta.
Origin and meaning
From reading and writing comes the idea in modern education of literacy, by which we generally mean having the ability to understand ideas expressed through the medium of words. From reckoning and figuring comes the modern idea of numeracy which means being able to understand ideas expressed in the medium of mathematics. There is no single word, equivalent to literacy or numeracy, that expresses writing and roughing (that is the ability to make – as in wheelwright, shipwright, Cartwright). In late 18th and early 19th century the role of schools in preparing children to work in manufacturing industry would have been seen to have had a greater vocational and economic relevance than it would today. 
The original three Rs identified by Sir William Curtis MP have equivalents in the Functional Skills of literacy, numeracy and ICT to be found in the modern day English education system.
There is an earlier reference to "reading, writing, and arithmetic." It comes from Saint Augustine's "The Confessions of Saint Augustine" AD 401, Book I - Translated by Edward Bouverie Pusey. "For those first lessons, reading, writing and arithmetic, I thought as great a burden and penalty as any Greek."
The phrase 'the three Rs' is used because each word in the phrase has a strong R phoneme (sound) at the beginning. The term is ironic, since someone with rudimentary language education would know that two of the original words do not actually begin with the letter R. The third R was more probably Reckoning, not as is more usually stated 'Rithmetic. Reckoning was a Victorian term for mental arithmetic and had been in use as such since the 14th century. The educationalist Louis P. Bénézet preferred "to read", "to reason", "to recite", adding, "by reciting I did not mean giving back, verbatim, the words of the teacher or of the textbook. I meant speaking the English language."
The Three Rs in the United States
During the 17th century, curriculum in the common schools (elementary) of the New England colonies was summed up as the "four Rs" - Reading 'Riting, "Rithmetic", and Religion.
Washington State Superintendent of Public Instruction, Terry Bergeson, identified the new 3 Rs from Robert Carkhuff's 3 Rs as Relating, Representing and Reasoning. Carkhuff was a self-published consultant paid $1 million to provide materials to help design Washington's controversial standards based education reform program. Terry Bergeson has pledged that that all would receive world class standards diplomas, yet one half of all students and three-quarters of minority students are on track to have their diplomas revoked in 2008 because they do not pass the new 3 Rs standard set by the WASL standards based assessment. While over half of US students will be required to pass similar High school graduation examinations, because of objections from parents and education experts, no more states have adopted such requirements and some have dropped them in 2006. Advocates of the traditional education question how students who struggle with basic skills can be expected to be more successful at higher developmental higher order thinking levels. States like California abandoned similar standards in the late 1990s in favor of returning to basic skills.
A more recent use of "the Three Rs" comes from the subject of CNC code generation by Edgecam Workflow:
- Obsolete Skill Set: The 3 Rs — Literacy and Letteracy in the Media Ages
- The Mirror of Literature Amusement and Instruction, Volume 5 by John Timbs, J. Limbird, 1825
- The story of the three Rs
- Education No 307
- Functional Skills
- L. P. Benezet, "The Teaching of Arithmetic I, II, III: The Story of an Experiment," Journal of the National Education Association, Volume 24(8): 241-244 (November 1935)
- Slosson, Edwin Emory. "The American Spirit in Education: A Chronicle of Great Teachers, Volume 33". Googe Books. Yale University Press. Retrieved 30 July 2014.
- Seattle Post-Intelligencer: Sound Off