Let’s assume, you are in a rush and you need a random number: What is the best way to produce a high-quality, uniformly distributed random integer number between 0 and 9, ideally using only mental math or, less ideally, tools that are commonly available (except for computers, calculators, smartphones and books, of course).
Asked
Active
Viewed 61 times
1
-
Is this common? http://www.random.org/integers/ – Amzoti Jan 18 '14 at 02:06
-
1Look at a digital clock and use the ones digit of the minute? – bradhd Jan 18 '14 at 02:06
-
1How fast are you with scissors and glue? :-D – J. W. Perry Jan 18 '14 at 02:40
-
This is more pencil-and-paper rather than mental, but: https://en.wikipedia.org/wiki/Middle-square_method – vadim123 Jan 18 '14 at 02:58
1 Answers
3
Toss a fair coin four times. Put a 1 if the toss is a head and a 0 otherwise. Make the four tosses into a string of 0s and 1s of length 4. For example you might get 0110. Convert this binary number to decimal; in the example you got 6. Toss it out and try again if the number is > 9.
ncmathsadist
- 49,383
-
For repeated tries, you can increase the efficiency by throwing 10 coins to produce 3 digits (try again if the number is in the (1000-1023 range) – leonbloy Jan 18 '14 at 03:48
-