There have been many attempts to focus on the most important things for the student to learn. Very likely, what was actually studied then differs quite a bit from the modern form of the subject. It has been instructive to me to watch adults in action to see just how well they have mastered and use these so-called basics.
Many people live in communities with impressive free libraries but do very little reading.
Similarly, while they can write, many high school and college graduates actually write very little. I often wonder at the fact that for centuries, the ability to read and write was considered a special and technical gift of a high order while today, many citizens possess these gifts and make little use of them. Arithmetic is usually said to be the mathematical subject that students should learn in elementary school while algebra and higher branches of math are learned later. Of course, with the justly famous National Council of Teachers of Mathematics' standards' emphasis on the value of teaching several branches of mathematics at early ages along with the introduction of reflective consideration of the students' feelings and pleasures in the subject, arithmetic is not what it once was in some schools. Still, quantity, shape, probability and other mathematical concepts are not used in the lives of adults for the benefits they could be.