h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Russian Peasant Multiplication - A22519226
Author: Icy North - U225620
Peer Review thread: F48874?thread=4137370

Entry: Using an Abacus for Addition and Subtraction - A20340235
Author: Leo of the sickly yellow thumb - U519437
Peer Review thread: F48874?thread=4158076

Entry: Divisibility - A22731914
Author: Icy North - U225620
Peer Review thread: F48874?thread=4161185

A good meaty one for all you mathematicians - let me know what you think.

Entry: Euclid - A13456082
Author: Gnomon - [ 3 stars - off to Budapest and Greece next week ] - U151503
Peer Review thread: F48874?thread=4180965

Entry: Constructions with a Ruler and a Compass - A24020506
Author: toy box - U208464

PR thread: F48874?thread=4360744

Entry: Gauss integers - A25022396
Author: toy box - U208464
PR thread: F48874?thread=4390109

If you are really curious about it, an older version can be found at A1125884.

Entry: Complex Numbers - an Introduction - A25082372
Author: Icy North - U225620
PR Thread : F48874?thread=4413408

Entry: Prime Numbers - A25209047
Author: Big Al - Member, Wessex Researchers Group, Keeper of Mnemonics, Patron Saint of Left Handers - U723247


PR Thread: F48874?thread=4413426

Entry: Envy-Free Cake Division - A27052922
Author: Icy North - U225620
PR Thread: F48874?thread=4595583

It's a cool subject. I seem to remember that there is a fair way of doing it with n people which doesn't rely on people calling out "Cut!". Like "You slice I choose" but with more steps. Can't remember how it goes though, but I saw a poster about it once.

If I haven't covered it, then I'd be interested to hear about it! Let me know if you remember anything.

I'm only intending to give a basic summary in this entry.

Icy

Hmm, perhaps something like this from w*k* (for three people)?

"One method continues the division to successively smaller "equal" portions. The first person divides the resource into what they believe are equal halves. The second then chooses a half, leaving the remainder for the first person. Each of these two people then divide their respective portions into thirds. The third person picks two of the resulting portions: one from the first person and one from the second person. If there are four people, each of the first three people divides their portions into fourths, and the process continues."

http://en.wikipedia.org/wiki/Fair_division

Thanks Dogster,

I make it a point not to read W*k* when I write an entry, but that is an interesting method, albeit impractical through the possible number of pieces you end up with. I'll look into it further and see if it slots in easily.

Icy

Yeah, I agree it's best not to make H2G2 a clone of w*k*. Unfortunately, when I googled 'fair cake sharing algorithm' it came right at the top and I'm very lazy so I just clicked it...

Entry: Leonhard Euler - Mathematician - A28224957
Author: Gnomon: U151503
PR Thread: F48874?thread=4706693

Entry: The Five Card Trick - A2496873
Author: Gnomon - U151503
Peer Review Thread - F48874?thread=4713178

Entry: Nano the Dwarf - A Guide to Decimal Prefixes - A28851546
Author: Icy North - U225620
Peer Review Thread - F48874?thread=4799585

Entry: Kibibytes and Yobibits - A Guide to Binary Prefixes - A29293545
Author: Icy North - U225620
Peer Review Thread: F48874?thread=4801844

Icy

Entry: The Square-Wheeled Bicycle - a Road of Hyperbolics? - A29887771
Author: Icy North - U225620
Peer Review thread: F48874?thread=4859545

We haven't had a good applied maths entry in Peer Review for a while - please come and add your mathematical opinions:

Entry: What Happens When You Drop a Slinky - A36656085
Author: Pinniped - U183682
Peer Review Thread: F48874?thread=5514233

Icy