# The Indisputable Santa Mathematical Advent CalendarDay 13

Happy 13th 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…

# The Indisputable Santa Mathematical Advent CalendarDay 12

Happy 12th 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…

As you’ll have gathered, one of the fundamental principles of our book is the absolute and unquestionable truth of Santa’s existence. However, even if you know that the big fellow is real, that doesn’t necessarily mean he’s easy to spot. For example, one of these three is Santa… but which one?

# The Indisputable Santa Mathematical Advent CalendarDay 11

Happy 11th 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…

Puzzle time:

We’ll reveal the answer to Friday’s tough Elfnigma tomorrow, so there’s still time to have a go at that one too.

# The Indisputable Santa Mathematical Advent CalendarDay 10

Happy 10th 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…

Puzzle time!

There’s a couple of days before we reveal the answer to the tough Elfnigma from yesterday, so there’s still time to have a go at that one.

# The Indisputable Santa Mathematical Advent CalendarDay 9

Happy 9th 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…

[EDIT: Two variants of this puzzle can be found HERE.]

Today, a tougher puzzle. We’ll give you the whole weekend to work it out. Solution on Monday…

# The Indisputable Santa Mathematical Advent CalendarDay 8

Happy 8th 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…

There’s a tougher-than-usual puzzle tomorrow, so today we’re keeping it light, with a joke:

# The Indisputable Santa Mathematical Advent CalendarDay 7

Happy 7th 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…

Another mini-puzzle today:

Enjoy!

# The Indisputable Santa Mathematical Advent CalendarDay 6

Happy 6th 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…

Another puzzle today:

And take note of this observation from Michael Baym:

# The Indisputable Santa Mathematical Advent CalendarDay 5

Happy 5th 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…

Something a bit different today. As part of the research for our book, we created a two-step Markov model to analyse the Queen’s Christmas Messages and generate tweets in the same style. We’ll be tweeting these out from now until she delivers her message (When you can test how accurate we were!).

Across her 64 messages (including a written message in 1969), our Liz has actually got through a remarkably wide range of topics (with admirably little repetition, given the unvarying nature of her brief!), so don’t be surprised if the Elizabot comes out with the occasional musing on magnets, bagpipes or football.