# 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.

Here are some of the (real) Queen’s most used – and least used – phrases over the years:

SOLUTION TO YESTERDAY’S PUZZLE

Scroll down for the solution…

.

.

.

.

.

.

.

.

.

.

.

.

Solution:

Santa’s favourite number is 2.083 (recurring), because it’s equal to 25/12 ! However, as some have noted, he evidently changes his mind mid-Atlantic, since he prefers 0.48 when in the US.

Congratulations to NealOlaf DoschkeRick Kaeser, Alistair Cunningham, Troy RRealityMinus3, Michael Rumney, Alberto Franceschini and Singing Hedgehog, who all submitted correct answers (or who all made it clear that they’d worked it out, at any rate!).