English

Carryless Arithmetic Mod 10

Number Theory 2014-09-17 v2

Abstract

We investigate what arithmetic would look like if carry digits into other digit position were ignored, so that 9 + 4 = 3, 5 + 5 = 0, 9 X 4 = 6, 5 X 4 = 0, and so on. For example, the primes are now 21, 23, 25, 27, 29, 41, 43, 45, 47, ... .

Cite

@article{arxiv.1008.4633,
  title  = {Carryless Arithmetic Mod 10},
  author = {David Applegate and Marc LeBrun and N. J. A. Sloane},
  journal= {arXiv preprint arXiv:1008.4633},
  year   = {2014}
}

Comments

7 pages. To the memory of Martin Gardner (October 21, 1914 -- May 22, 2010). Revised version (with a number of small improvements), July 7 2011

R2 v1 2026-06-21T16:05:48.322Z