# How to fill Philbert – MINI-PUZZLE

Here’s a bonus puzzle inspired by a recent Christmas purchase.

I bought this jolly fellow in Covent Garden:

We named him Philbert, for some reason.

As you can see, Philbert has two cubes in his stomach (dice, basically), each of which has a digit on each face. By rearranging the dice, you can count the days until Christmas.

Puzzle 1 (EASY)

# More Christmas Maths!

OK, so I’ve come out of my long period of digital aestivation and returned to my blog and to various social media platforms.

Rather excitingly, a new version of Hannah and my Christmas maths book is out today! There’s a new chapter about cake, so that’s nice.

There’s also a US version this year, in which we spell things differently and provide extra info on bizarre British festive traditions (though how they get through the day without detonating a small explosive in a cardboard tube and fighting over a pack of mini-screwdrivers, I have no idea).

The UK Edition on Amazon.co.uk

The US Edition on Amazon.com

Here are the two new covers, side by side:

UK Version

US Version

# Happy Boxing Day from The Indisputable Santa Mathematical Advent Calendar!

## Happy Boxing Day!

Throughout the month, to accompany the release of our book on the Mathematics of ChristmasHannah Fry & I were tweeting out Christmathsy bits and pieces, one a day, advent calendar style.

A final post, to provide the solution to Friday’s puzzle.

# Merry Christmas from The Indisputable Santa Mathematical Advent Calendar!

## Merry Christmas!

Throughout the month, to accompany the release of our book on the Mathematics of ChristmasHannah Fry & I were tweeting out Christmathsy bits and pieces, one a day, advent calendar style.

Thanks for following the Indisputable Santa Mathematical Advent Calendar. Just a few loose ends to wrap up, with a solution to our Christmas Eve puzzle today, with the solution to Friday’s puzzle (Santa’s Dressing Room Disasters) to come tomorrow…

# The Indisputable Santa Mathematical Advent CalendarDay 24

Happy 24th of December!

Throughout the month, to accompany the release of our book on the Mathematics of ChristmasHannah Fry & I are tweeting out Christmathsy bits and pieces, one a day, advent calendar style. Assuming we don’t run out of ideas, that is…

And so, the final day of the Impossible Santa Mathematical Advent Calendar has arrived. Santa is about to set off, but there’s still time to take a quick register of the reindeer:

“Now, Dasher! Now, Dancer! Now, Prancer, and Vixen!
“On, Comet! On, Cupid! On, Donner and Blitzen!”*

But, wait a minute… Which one is which?

The solution to this puzzle will be posted tomorrow (Christmas!) with the solution to yesterday’s Dressing Room Disaster puzzles to follow on Boxing Day (mainly because the explanation of the solution is taking a while to write up!).

Merry Christmas everyone!

* I was interested to learn that “Donner and Blitzen” were actually named “Dunder and Blixen” (or other variations thereof) in early versions of the text. I suppose the versions in Rudolph the Red-Nosed Reindeer must have ultimately overwhelmed these alternatives.

# The Indisputable Santa Mathematical Advent CalendarDay 23

Happy 23rd of December!

Throughout the month, to accompany the release of our book on the Mathematics of ChristmasHannah Fry & I are tweeting out Christmathsy bits and pieces, one a day, advent calendar style. Assuming we don’t run out of ideas, that is…

We’re getting to the business end of this advent calendar now and the puzzling is getting serious. High stakes stuff today, as Santa needs help getting into that iconic costume…

Two levels of challenge…

Merry:

And Mayhem!

(For the advanced puzzle, note that not every path starting and ending in A involves a complete circuit of the pole. For example, if Santa follows the path ABCDBA, he has not completed a circuit.)

Each time you enter a room, you MUST follow all of the instructions written there.

For extra credit, try to find Santa’s shortest possible path in each case. And for extra extra credit, prove that your path really is the shortest.