Mathematical Geology

, Volume 23, Issue 4, pp 541–548 | Cite as

Generating random numbers in the field

  • Carter Bays
  • W. E. Sharp


A pseudo-random number generator which is easy to remember and uses the very simple sequences 321 and 123 can be readily implemented on any available hand calculator. The generator is given by the recursive relation: Ri=321 × Ri−1+123, and is initiated using any 5-digit number for Ri−1and saving the rightmost 5 digits of Rifor the next Ri−1;the two leftmost digits of Rithen yield an acceptable random number between 00 and 99. Alternately, a much better generator is given which can be jotted down in a notebook or taped to the back of your calculator.

Key words

random numbers hand calculator mixed congruential 


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Copyright information

© International Association for Mathematical Geology 1991

Authors and Affiliations

  • Carter Bays
    • 1
  • W. E. Sharp
    • 2
  1. 1.Department of Computer ScienceUniversity of South CarolinaColumbia
  2. 2.Department of Geological SciencesUniversity of South CarolinaColumbia

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