# Blog

## Archive

Show me a Random Blog Post**2017**

### Mar 2017

The End of Coins of Constant WidthDragon Curves II

### Feb 2017

The Importance of Estimation Error### Jan 2017

Is MEDUSA the New BODMAS?**2016**

**2015**

**2014**

**2013**

**2012**

## Tags

folding paper folding tube maps london underground platonic solids rhombicuboctahedron raspberry pi weather station programming python php inline code news royal baby probability game show probability christmas flexagons frobel coins reuleaux polygons countdown football world cup sport stickers tennis braiding craft wool emf camp people maths trigonometry logic propositional calculus twitter mathslogicbot oeis pac-man graph theory video games games chalkdust magazine menace machine learning javascript martin gardner reddit national lottery rugby puzzles advent game of life dragon curves fractals pythagoras geometry triangles european cup dates palindromes chalkdust christmas card bubble bobble asteroids final fantasy curvature binary arithmetic bodmas statistics error bars estimation accuracy misleading statistics pizza cutting**2016-12-28 06:49:35**

## Christmas (2016) is Over

More than ten correct solutions to this year's Advent calendar puzzle competition were submitted on Christmas Day, so the competition is now over.
(Although you can still submit your answers to get me to check them.) Thank-you to everyone who took part in the puzzle, I've had a lot of
fun watching your progress and talking to you on Twitter, Reddit, etc. You can find all the puzzles and answers (from 1 January) here.

The (very) approximate locations of all the entries I have received so far are shown on this map:

This year's winners have been randomly selected from the 29 correct entries on Christmas Day. They are:

1 | Jack Jiang |

2 | Steve Paget |

3 | Joe Gage |

4 | Tony Mann |

5 | Stephen Cappella |

6 | Cheng Wai Koo |

7 | Demi Xin |

8 | Lyra |

9 | David Fox |

10 | Bob Dinnage |

Your prizes will be on their way in early January.

Now that the competition has ended, I can give away a secret. Last year, Neal
suggested that it would be fun if a binary picture was hidden in the answers. So this year I hid one. If you write all the answers in binary, with
each answer below the previous and colour in the 1s black, you will see this:

I also had a lot of fun this year making up the names, locations, weapons and motives for the final murder mystery puzzle. In case you missed them these were:

# | Murder suspect | Motive |

1 | Dr. Uno (uno = Spanish 1) | Obeying nameless entity |

2 | Mr. Zwei (zwei = German 2) | To worry others |

3 | Ms. Trois (trois = French 3) | To help really evil elephant |

4 | Mrs. Quattro (quattro = Italian 4) | For old unknown reasons |

5 | Prof. Pum (pum = Welsh 5) | For individual violent end |

6 | Miss. Zes (zes = Dutch 6) | Stopping idiotic xenophobia |

7 | Lord Seacht (seacht = Irish 7) | Suspect espied victim eating newlyweds |

8 | Lady Oito (oito = Portuguese 8) | Epic insanity got him today |

9 | Rev. Novem (novem = Latin 9) | Nobody in newsroom expected |

# | Location | Weapon |

1 | Throne room | Wrench (1 vowel) |

2 | Network room | Rope (2 vowels) |

3 | Beneath reeds | Revolver (3 vowels) |

4 | Edge of our garden | Lead pipe (4 vowels) |

5 | Fives court | Neighbour's sword (5 vowels) |

6 | On the sixth floor | Super banana bomb (6 vowels) |

7 | Sparse venue | Antique candlestick (7 vowels) |

8 | Weightlifting room | A foul tasting poison (8 vowels) |

9 | Mathematics mezzanine | Run over with an old Ford Focus (9 vowels) |

Finally, well done to Scott,
Matthew Schulz,
Michael Gustin,
Daniel Branscombe,
Kei Nishimura-Gasparian,
Henry Hung,
Mark Fisher,
Jon Palin,
Thomas Tu,
Félix Breton,
Matt Hutton,
Miguel,
Fred Verheul,
Martine Vijn Nome,
Brennan Dolson,
Louis de Mendonca,
Roni,
Dylan Hendrickson,
Martin Harris,
Virgile Andreani,
Valentin Valciu,
and Adia Batic for submitting the correct answer but being too unlucky to win prizes this year. Thank you all for taking part and I'll see you
next December for the next competition.

### Similar Posts

Christmas (2016) is Coming! | Christmas (2015) is Over | Christmas (2015) is Coming! | Christmas Card 2016 |

### Comments

Comments in green were written by me. Comments in blue were not written by me.

**2017-01-19**

Thanks for setting this all up; I had a lot of fun solving the puzzles every day (and solving half them again when my cookie for the site somehow got deleted). I'll be sure to participate next time too!

SC

**2016-12-28**

Jack

**Add a Comment**

**2016-12-20 09:21:56**

## Christmas Card 2016

Last week, I posted about the Christmas card I designed on the Chalkdust blog.

The card looks boring at first glance, but contains 12 puzzles. Converting the answers to base 3, writing them in the boxes on the front, then colouring the 1s green and 2s red will reveal a Christmassy picture.

If you want to try the card yourself, you can download this pdf. Alternatively, you can find the puzzles below and type the answers in the boxes. The answers will be automatically converted to base 3 and coloured...

# | Answer (base 10) | Answer (base 3) | ||||||||

1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |

12 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |

- The square number larger than 1 whose square root is equal to the sum of its digits.
- The smallest square number whose factors add up to a different square number.
- The largest number that cannot be written in the form \(23n+17m\), where \(n\) and \(m\) are positive integers (or 0).
- Write down a three-digit number whose digits are decreasing. Write down the reverse of this number and find the difference. Add this difference to its reverse. What is the result?
- The number of numbers between 0 and 10,000,000 that do not contain the digits 0, 1, 2, 3, 4, 5 or 6.
- The lowest common multiple of 57 and 249.
- The sum of all the odd numbers between 0 and 66.
- One less than four times the 40th triangle number.
- The number of factors of the number \(2^{756}\)×\(3^{12}\).
- In a book with 13,204 pages, what do the page numbers of the middle two pages add up to?
- The number of off-diagonal elements in a 27×27 matrix.
- The largest number, \(k\), such that \(27k/(27+k)\) is an integer.

### Similar Posts

Christmas (2016) is Over | Christmas (2016) is Coming! | Christmas (2015) is Over | Christmas (2015) is Coming! |

### Comments

Comments in green were written by me. Comments in blue were not written by me.

**2016-12-20**

Dan Whitman

**2016-12-20**

Matthew

**2016-12-20**

Dan Whitman

**Add a Comment**

**2016-11-27 15:57:54**

## Christmas (2016) is Coming!

This year, the front page of mscroggs.co.uk will feature an advent calendar, just like last year. Behind each door, there will be a puzzle with a three digit solution. The solution to each day's puzzle forms part of a murder mystery logic puzzle in which you have to work out the murderer, motive, location and weapon used: the answer to each of these murder facts is a digit from 1 to 9 (eg. The murderer could be 6, the motive 9, etc.).

As you solve the puzzles, your answers will be stored in a cookie. Behind the door on Christmas Day, there will be a form allowing you to submit your answers. The winner will be randomly chosen from all those who submit the correct answer on Christmas Day. Runners up will then be chosen from those who submit the correct answer on Christmas Day, then those who submit the correct answer on Boxing Day, then the next day, and so on. As the winners will be chosen randomly,

**there is no need to get up at 5am on Christmas Day this year**!The winner will win this array of prizes:

I will be adding to the pile of prizes throughout December. Runners up will get a subset of the prizes. The winner and runners up will also win an mscroggs.co.uk 2016 winners medal:

To win a prize, you must submit your entry before the end of 2016. Only one entry will be accepted per person. Once ten correct entries have been submitted, I will add a note here and below the calendar. If you have any questions, ask them in the comments below or on Twitter.

So once December is here, get solving! Good luck and have a very merry Christmas!

Edit: added picture of this year's medals.

Edit: more than ten correct entries have been submitted, list of prize winners can be found here.
You can still submit your answers but the only prize left is glory.

### Similar Posts

Christmas (2016) is Over | Christmas (2015) is Over | Christmas (2015) is Coming! | Christmas Card 2016 |

### Comments

Comments in green were written by me. Comments in blue were not written by me.

**2016-12-27**

Matthew

**2016-12-27**

Another Matthew

**2016-12-25**

Lyra

**2016-12-25**

Louis

**2016-12-25**

Matthew

**Add a Comment**

**2016-01-01 11:32:52**

## Christmas (2015) is Over

The deadline for entering the 2015 Advent calendar competition has now passed. You can see all the puzzles and their answers here.

Thank-you to everyone who took part in the competition! In total, 23 people submitted answers to the puzzles. Every one of these had correct answers to at least 18 of the puzzles. The winners are as follows:

# | Name | Details |

1 | Scott | All correct at 5:00:18 GMT on Christmas Day |

2 | Louis de Mendonca | All correct at 5:00:32 GMT on Christmas Day |

3 | Alex Bolton | All correct at 5:00:34 GMT on Christmas Day |

4 | Martin Harris | All correct at 6:15 GMT on Christmas Day |

5 | Linus Hamilton | All correct at 14:12 GMT on Christmas Day |

6 | Zephi | All correct at 20:40 GMT on Christmas Day |

7 | Daniel Chiverton | All but one (5 December) correct at 5:00:24 GMT on Christmas Day |

8 | Jon Palin | All but one (12 December) correct at 5:00:34 GMT on Christmas Day |

9 | Kathryn Coffin | All but one (5 December) correct at 6:28 GMT on Christmas Day |

10 | Félix Breton | All but one (15 December) correct at 9:05 GMT on Christmas Day |

I will be in touch will all the entrants in the next few days and I will post pictures of prizes here once they are on their way!

I have already started working on puzzles for next year's (in fact

*this year's*) calendar, so make sure you're back here in December...### Similar Posts

Christmas (2016) is Over | Christmas (2016) is Coming! | Christmas (2015) is Coming! | Christmas Card 2016 |

### Comments

Comments in green were written by me. Comments in blue were not written by me.

**2016-07-14**

Matthew

**2016-01-16**

stephan

**Add a Comment**

**2015-11-24 15:05:00**

## Christmas (2015) is Coming!

This year, the front page of mscroggs.co.uk will feature an advent calendar. Behind each door, there will be a puzzle with a three digit solution.

As you solve the puzzles, your answers will be stored in a cookie. Behind the door on Christmas Day, there will be a form allowing you to submit your answers. The first person to submit the correct answers will win this array of prizes:

The prizes include an mscroggs.co.uk t-shirt, a DVD of Full Frontal Nerdity and a beautiful mscroggs.co.uk 2015 winner's medal:

I will be adding to the pile of prizes throughout December.

The next nine people to submit the correct answers will win a winner's medal plus a smaller goody bag of prizes. If less than ten correct entries are submitted, prizes will be given to those with one incorrect answer, then those with two incorrect answers and so on.

Each day's puzzle (and the entry form on Christmas Day) will be available from 5:00am GMT.

To win a prize, you must submit your entry before the start of 2016. Only one entry will be accepted per person. Once ten correct entries have been submitted, I will add a note here and below the calendar. If you have any questions, ask them in the comments below or on Twitter.

So once December is here, get solving! Good luck and have a very merry Christmas!

Edit: The winners and answers can now be found here.

### Similar Posts

Christmas (2016) is Over | Christmas (2016) is Coming! | Christmas (2015) is Over | Christmas Card 2016 |

### Comments

Comments in green were written by me. Comments in blue were not written by me.

**2015-12-28**

Matthew

**2015-12-28**

Anonymous2

**2015-12-25**

Matthew

**2015-12-25**

Are you allowed to tell me if I am correct?

Anonymous1

**2015-12-25**

hint hint

Anonymous

**Add a Comment**

2017-02-03