# Best way to generate random numbers at home? **URL:** \ **Category:** Factual Questions\ **Created:** [January 22, 2009, 6:21pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490 "2009-01-22T18:21:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [January 22, 2009, 6:21pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/1 "2009-01-22T18:21:07Z")
Since the topic of random numbers is in the air tonight… this was in my to-ask list since my d3 thread: What is the best way to generate random numbers at home? A professor once said to pick a big fat book with thin pages (dictionary, phone book) and open it anywhere and take only the last digit. Repeat as needed and discard out of range numbers if necessary. For example, if you need a random number from 1 to 47, you open the first page, that is your last digit (units). Repeat for the next digit (tens). Here you can map 6-0 as 1-5 or discard them. If you got a 48, then start from the beginning. The idea here being that with fat enough fingers and thin enough pages, no matter where you are biased to open the book, the last digit was close enough to random. Is this really the best way to generate random numbers with stuff generally found at home and without resorting to making a mess, using higher math, etc? ---
**Author:** ![Capt.Ridley\_s\_Shooting\_Party](https://avatars.discourse-cdn.com/v4/letter/c/cc9497/32.png) [@Capt.Ridley\_s\_Shooting\_Party](https://boards.straightdope.com/u/Capt.Ridley_s_Shooting_Party)\ **Post date:** [January 22, 2009, 6:22pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/2 "2009-01-22T18:22:20Z")
Using the random number button on any decent calculator 😛 ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [January 22, 2009, 6:44pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/3 "2009-01-22T18:44:58Z")
> **[RANDOM.ORG - True Random Number Service](https://www.random.org/)** > > RANDOM.ORG offers true random numbers to anyone on the Internet. The randomness comes from atmospheric noise, which for many purposes is better than the pseudo-random number algorithms typically used in computer programs. Have a look at integers. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [January 22, 2009, 6:57pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/4 "2009-01-22T18:57:35Z")
Roll dice. ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [January 22, 2009, 7:30pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/5 "2009-01-22T19:30:15Z")
I am sorry I didn’t specify. No dice, no computers. I mean common daily objects in your grandma’s house. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [January 22, 2009, 7:37pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/6 "2009-01-22T19:37:44Z")
Shuffle a deck of cards. Bonus: convert from base-52 (or base-13) to base-10. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [January 22, 2009, 7:46pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/7 "2009-01-22T19:46:41Z")
> [@Sapo](#): > > I am sorry I didn’t specify. No dice, no computers. I mean common daily objects in your grandma’s house. If cards are as forbidden as dice, do coins count? ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [January 22, 2009, 8:01pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/8 "2009-01-22T20:01:53Z")
How many random numbers do you need? ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [January 22, 2009, 8:03pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/9 "2009-01-22T20:03:10Z")
Your brain. Just start calling out numbers. ---
**Author:** ![Walton\_Firm](https://avatars.discourse-cdn.com/v4/letter/w/45deac/32.png) [@Walton\_Firm](https://boards.straightdope.com/u/Walton_Firm)\ **Post date:** [January 22, 2009, 8:14pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/10 "2009-01-22T20:14:42Z")
> [@Sage\_Rat](#): > > Your brain. Just start calling out numbers. That’s a bad method. People are very bad at avoiding patterns. There are interesting experiments wherein people have been asked to type “as randomly as possible” on a keyboard – it turns out to be not very difficult to write a computer program which can predict, with surprising accuracy, which key they will hit before they hit it. ---
**Author:** ![Sapo](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sapo](https://boards.straightdope.com/u/Sapo)\ **Post date:** [January 22, 2009, 8:15pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/11 "2009-01-22T20:15:05Z")
> [@erislover](#): > > How many random numbers do you need? er, a random number of them? 🙂 Coins are dice, of course. And they only do 0 or 1. Say that at any time you need a number from 1 to 17, to choose from options. Pick a student at random, give something to a child, etc. ---
**Author:** ![YamatoTwinkie](https://avatars.discourse-cdn.com/v4/letter/y/cc9497/32.png) [@YamatoTwinkie](https://boards.straightdope.com/u/YamatoTwinkie)\ **Post date:** [January 22, 2009, 8:20pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/12 "2009-01-22T20:20:31Z")
> [@Sapo](#): > > er, a random number of them? 🙂 > Coins are dice, of course. And they only do 0 or 1. …which naturally makes it a good candidate for picking a random binary number, which you can then convert to decimal. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [January 22, 2009, 8:42pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/13 "2009-01-22T20:42:22Z")
> [@Sapo](#): > > I am sorry I didn’t specify. No dice, no computers. I mean common daily objects in your grandma’s house. Before polyhedral dice (i.e., dice other than the normal six-siders) were generally available, D&D players used numbered chits. Make yourself some identical bits of paper or cardstock (maybe 1/2" square sections of index card) and write each number you want to randomize from on a bit. Throw all of them into a hat or coffee mug or something. Shake. Pick one. ---
**Author:** ![tim-n-va](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim-n-va/32/3001_2.png) [@tim-n-va](https://boards.straightdope.com/u/tim-n-va)\ **Post date:** [January 22, 2009, 9:07pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/14 "2009-01-22T21:07:18Z")
> [@Sapo](#): > > A professor once said to pick a big fat book with thin pages (dictionary, phone book) and open it anywhere and take only the last digit. Repeat as needed and discard out of range numbers if necessary. I would modify that to the next-to-last digit of the page number to avoid having to decide which of the two facing pages to use. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [January 22, 2009, 9:12pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/15 "2009-01-22T21:12:47Z")
Use a telephone directory, open in the middle, take the final 4 digits of each phone number to get a random string of numbers. ---
**Author:** ![Mosier](https://avatars.discourse-cdn.com/v4/letter/m/7ea924/32.png) [@Mosier](https://boards.straightdope.com/u/Mosier)\ **Post date:** [January 22, 2009, 9:16pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/16 "2009-01-22T21:16:06Z")
deck of cards with the J, Q, K removed seems like the fastest way to me. ---
**Author:** ![Bootis](https://avatars.discourse-cdn.com/v4/letter/b/e8c25b/32.png) [@Bootis](https://boards.straightdope.com/u/Bootis)\ **Post date:** [January 22, 2009, 9:17pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/17 "2009-01-22T21:17:35Z")
The random page method is no good, I find when I open books Ive read before randomly to read on the toilet, its often the exact same page as other times. Many books will open more readily to certain pages. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [January 22, 2009, 9:21pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/18 "2009-01-22T21:21:23Z")
Does your grandmother have a tile floor or counter? Throw a fist full of salt in the air, and count how many grains land in each square. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [January 22, 2009, 9:28pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/19 "2009-01-22T21:28:32Z")
> [@Sapo](#): > > Say that at any time you need a number from 1 to 17, to choose from options. Pick a student at random, give something to a child, etc. Using a telephone directory as described above get a four digit number from 0000 to 9999. Use pen and paper to divide by 17, with remainder. The remainder will give you a random integer from 0 to 16. Add 1. ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [January 22, 2009, 9:28pm UTC](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490/20 "2009-01-22T21:28:38Z")
Look at the second hand of a clock. Divide the 60 seconds into equal segments, and see what you get. That gets you 2,3,4,6,12,15,20, or 30 choices. [Next page](https://boards.straightdope.com/t/best-way-to-generate-random-numbers-at-home/482490.md?page=2)