Math Is Fun Forum

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Little Pigley Farm

I enjoy doing cross-number puzzles...& here's one of my favourites.

No advanced maths required - just basic arithmetic. Needs lots of logic.

Enjoy!

Last edited by phrontister (2009-12-22 09:59:28)

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Re: Little Pigley Farm

Hi mathsyperson,

I just came across Plutoman's Cross-number puzzle for 2008 thread featuring his Mathematical Maelstrom puzzles. They're terrific! I love them, and have done them all.

His Lexoku puzzles, particularly the more difficult ones (they're difficulty-rated now), are definitely worth doing too.

The link to his site is Pluto Puzzles

Anyway, I saw from your MM puzzle posts how much you liked them and so I thought that I'd revive my Little Pigley Farm thread, which has sunk off the page and drawn zero comment along the way. It's about the same order of difficulty as Plutoman's MMs, but the nicely interwoven storyline gives it a very different feel. Underneath hides some tricky logic for good grappling action.

Someone who has solved it said that it was one of the best number puzzles he's ever come across, and he highly recommends it to anyone who enjoys doing number puzzles. It's had quite a bit of airplay on the internet, but under a different title. My title is the one from the book in which I first saw it.

Forgive me for bumping this one up to the surface again, but I'd like to give it a second chance as I think it's too good a puzzle to just pass everyone by.

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

plutoman

Member

Registered: 2008-01-06

Posts: 27

Re: Little Pigley Farm

I've finally got around to doing Little Pigley Farm! Great puzzle! I wish I could be that inventive. Makes my puzzles, with their clues like A = 2B, seem rather dull.
Anyway, Little Pigley Farm was a thoroughly enjoyable puzzle. Took me a while to get started. The first 20% of the puzzle took 80% of the time! Anyone else had a go at it?

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Re: Little Pigley Farm

Hi plutoman,

Glad you solved Little Pigley Farm, and that you enjoyed it.

I wish I could be that inventive. Makes my puzzles, with their clues like A = 2B, seem rather dull.

These storyline puzzles get me in, that's for sure, and, unlike most other number puzzles, I revisit them from time to time. I've posted another one - Callous Count Crewell - that I'm sure you'll like. In some ways it's even better than Little Pigley Farm!

But none of your puzzles are dull at all! I've done all of your Mathematical Maelstroms, and am often impressed by the cleverly-constructed clues.

I see you're making good use of that uniqueness-checking program for your MM puzzles!

Last edited by phrontister (2009-12-10 18:09:19)

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Re: Little Pigley Farm

For anyone wondering how on earth you can get started, here are some helpful comments from "Cross Number Puzzles", an excellent book by Dr. Rainer Typke. The book features 30 good puzzles and the comments are specifically about them, but they apply equally well to other such puzzles.

I still remember how tough it was for me to find a starting point in my first cross number puzzle!

Cross number puzzles look like crossword puzzles, but the grid contains numbers instead of words. Most of the clues do not give enough information for filling in numbers straight away. Instead, they either provide hints to the relations between entries or give certain helpful (number theoretic) properties of the entries.

When solving a cross number puzzle it is a good idea to keep track of a set of digits for every box of the grid, as well as a set of possible numbers for some clues. Using the clues given, you can narrow down the possibilities until the solution is finally clear.

He gives the following "tips and tricks" (among others):

It usually helps to mark relations. If there is a group of numbers that depend on one another, it is a good idea to keep their relations in mind when you find information about one of them. There might be only very few possible number combinations that satisfy these dependencies, which might help with getting started with a puzzle.

Looking at end digits can help, not only for sums and differences, but also for quotients and products. For example, if two odd end digits are multiplied, the resulting number has again an odd end digit.

Under "Getting started", Dr. Typke says:

Getting started is often the most difficult part of solving a cross number puzzle.

- Look for numbers with very few possibilities like two-digit square numbers, cubic numbers or high powers.
- Try to find a small set of numbers that depend on one another and intersect in the grid.
- Take the numbers of digits into consideration if you have squares or products.
- Identify numbers that are frequently referred to. While this might not lead you to a good starting point, it will still speed up the solution.

I hope that helps. Dr. Typke's advice would sure have come in handy with my first cross number puzzle!

Last edited by phrontister (2009-12-15 20:04:13)

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Little Pigley Farm

Hi phrontister;

I just started working on this one, so it will be a while before I get anything.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Re: Little Pigley Farm

Hi Bobby,

In 2003 I asked Rainer Typke to let me know if he could work out how his solver could deal with this puzzle, but he was too busy at the time (he'd been kind enough to help me with a couple of others that I had a bit of trouble with in transcribing them into the required format).

I might have another go at it sometime...maybe after I totally give up on kaskusid's "Prove this" puzzle!

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Little Pigley Farm

Hi phrontister;

Great that you were able to contact him. His solver is a nice program.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,879

Re: Little Pigley Farm

Hi all,

I made a small alteration to the preamble regarding the date of the puzzle and the correctness check by replacing them with the "Find:" questions (2nd paragraph). The main puzzle solving remains unchanged.

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"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson