# Category: Kids

## Le Monde puzzle [#1083]

A Le Monde mathematical puzzle that seems hard to solve without the backup of a computer (and just simple enough to code on a flight to Montpellier): Given the number N=2,019, find a decomposition of N as a sum of non-trivial powers of integers such that (a) the number of integers in the sum is […]

## efficiency and the Fréchet-Darmois-Cramèr-Rao bound

Following some entries on X validated, and after grading a mathematical statistics exam involving Cramèr-Rao, I came to wonder at the relevance of the concept of efficiency outside [and even inside] the restricted case of unbiased estimators. The general (frequentist) version is that the variance of an estimator δ of [any transform of] θ […]

## L’enfant de poussière [book review]

I read this book in French, as this was the language in which it was written and also because I was given a free copy for writing a review! This is a rather unusual book, the first volume of a series called the cycle of Syffe (where Syffe is both the main character and the […]

## estimation exam [best of]

Yesterday, I received a few copies of our CRC Press Handbook of Mixture Analysis, while grading my mathematical statistics exam 135 copies. Among the few goodies, I noticed the always popular magical equality E[1/T]=1/E[T] that must have been used in so many homeworks and exam handouts by now that it should become a folk theorem. […]

## the adoration of the golden car

As the demonstrations by the “gilets jaunes” become a fixture of French Saturdays, the French government is gradually giving up on the reforms it had started and is in particular catering to the car [and motorbike] lobby that started the protests. The symbol itself comes from the yellow fluorescent jackets found in every car and […]

## Le Monde puzzle [#1081]

A “he said-she said” Le Monde mathematical puzzle (again in the spirit of the famous Singapore high-school birthdate problem): Abigail and Corentin are both given a positive integer, a and b, such that a+b is either 19 or 20. They are asked one after the other and repeatedly if they are sure of the other’s […]

## the future of conferences

The last issue of Nature for 2018 offers a stunning collection of science photographs, ten portraits of people who mattered (for the editorial board of Nature), and a collection of journalists’ entries on scientific conferences. The later point leading to interesting questioning on the future of conferences, some of which relate to earlier entries on […]

## and it only gets worse…

““This is absolutely the stupidest thing ever,” said Antar Davis, 23, a former zookeeper who showed up in the elephant house on Friday to take one last look at Maharani, a 9,100-pound Asian elephant, before the zoo closed.” The New York Times, Dec 29, 2018 “The Trump administration has stopped cooperating with UN investigators over […]

## Treasure Island

Just spent a wonderful hour listening to excepts from Stevenson’s Treasure Island while cooking dinner… Actually promoting a new translation (in French) in a much more colloquial version than the one I read as a child. I never get enough of this story (even though Kidnapped remains my favourite and not only mine’s!). As a […]

## Le Monde puzzle [#1076]

A cheezy Le Monde mathematical puzzle : (which took me much longer to find [in the sense of locating] than to solve, as Warwick U does not get a daily delivery of the newspaper [and this is pre-Brexit!]): Take a round pizza (or a wheel of Gruyère) cut into seven identical slices and turn one […]