A google.com search for L P Benezet yields quite a lot of information, including the following:

THE BENEZET CENTER at
http://www.inference.phy.cam.ac.uk/sanjoy/benezet/index.html

At this site you can see the three articles by L. P. Benezet, separately or as one file [html and pdf] and download them, and much more very interesting information. For example, click on Rote Learning at the site for interesting results on some problems. Click on Hassler Whitney and you will see some interesting writing of a well-known mathematician (deceased) on Benezet and his way of thinking about arithmetic and its teaching.

From the website: Over 70 years ago in Manchester, New Hampshire, children learnt no formal arithmetic until grade 6 (about age 11).
The program's creator, Superintendent Louis Benezet, describes it like this: In the fall of 1929 I made up my mind to try the experiment of abandoning all formal instruction in arithmetic below the seventh grade and concentrating on teaching the children to read, to reason, and to recite - my new Three R's. And by reciting I did not mean giving back, verbatim, the words of the teacher or of the textbook. I meant speaking the English language. I picked out five rooms - three third grades, one combining the third and fourth grades, and one fifth grade.

The paragraph above is from the first part of Benezet's classic three-part paper. At the Benezet Center at http://www.inference.phy.cam.ac.uk/sanjoy/benezet/index.html the website caretaker cautions, as follows:

Careful! Benezet did not advocate abandoning arithmetic instruction, only the mindless drill that goes with most formal instruction. This distinction has often been neglected. Here is the editors'
introduction to Benezet's paper as abridged and adapted in C.W.
Hunnicutt and William J. Iverson, eds., Research in the Three R's (New York: Harper, 1958), pp. 397-400:

A great controversy in arithmetic has centered on the question "When should systematic instruction in arithmetic begin?" Superintendent Benezet heaped fuel on the flames with his famous series of articles describing a city-wide tryout of an idea. He forcefully advocated "postponement of arithmetic" to Grade 7 or at least until Grade 6, though the reader will discover that he advocated postponement only of formal arithmetic. Actually he filled the early years with "meaningful" and "significant" arithmetic experiences. This study, often misquoted, has been used to support postponement of all organized arithmetic teaching.

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Jerry P. Becker
Curriculum & Instruction
Southern Illinois University
Carbondale, IL 62901-4610
Phone: (618) 453-4241 [O]
(618) 457-8903 [H]
Fax: (618) 453-4244
E-mail: jbecker@siu.edu