… if $B_1$, $B_2$, $\ldots$, $B_n$ are $n$ bases of an $n$-dimensional vector space $V$ (not necessarily distinct or disjoint), then there exists an $n \times n$ grid of vectors ($v_{ij}$) such that

1. the $n$ vectors in row $i$ are the members of the $i$th basis $B_i$ (in some order), and

2. in each column of the matrix, the $n$ vectors in that column form a basis of $V$.

Fan of the site Ravi Fernando has written in to tell us about his high score at the “is this prime?” game: a cool century!

I’ve been a fan of your “Is this prime?” game for a while, and after seeing your blog post from last May, I thought I’d say hi and send you some high scores. Until recently, my record was 89 numbers (last March 12), which I think may be the dot in the top right of your “human scores” graph. But I tried playing some more a couple weeks ago, and I found I can go a little faster using my computer’s y/n buttons instead of my phone’s touch screen. It turns out 100 numbers is possible!

Watch in amazement:

But, to the delight of prime fans everywhere, he didn’t stop there:

Today I even got 107 – good to have a prime record again.

Well done, Ravi!

Now is a good time to point out that the data on every attempt ever made at the game is available to download, in case you want to do your own analysis: at time of writing, there have been over 625,000 attempts, and 51 is still the number that catches people out the most.

It was George Boole’s bicentenary in 2015, so the Heslam Trust is a bit slow to reveal its plans to erect a statue of the great man in his home town of Lincoln.

There’s already a bust of Boole in University College, Cork, installed in plenty of time for the bicentenary. Here’s a picture of me and HRH Poppy Dog standing next to it, last Summer.

Why should I worry about dying? It’s not going to happen in my lifetime!

Raymond Smullyan, This Book Needs No Title (1986)

This week, the mathematical community has lost not one but two of its most beloved practitioners. Earlier this week, Swedish statistician Hans Rosling passed away aged 68, and today it’s been announced that author and logician Raymond Smullyan has also died, aged 97.

The next issue of the Carnival of Mathematics, rounding up blog posts from the month of January, and compiled by Manan, is now online at Math Misery.

The Carnival rounds up maths blog posts from all over the internet, including some from our own Aperiodical. See our Carnival of Mathematics page for more information.

Welcome to #104 of the Math Teachers At Play (MTaP) blog carnival. A blog carnival is a regular blogging round up coordinated by someone (in this case Denise Gaskins) that moves around different blogs each edition. This time, I’m taking a turn.

Hi! I’m Dani Poveda. This is my first post here on The Aperiodical. I’m from Spain, and I’m not a mathematician (I’d love to be one, though). I’m currently studying a Spanish equivalent to HNC in Computer Networking. I’d like to share with you some of my inquiries about some numbers. In this case, about triangular square numbers.

I’ll start at the beginning.

I’ve always loved maths, but I wasn’t aware of the number of YouTube maths channels there were. During the months of February and March 2016, I started following some of them (Brady Haran’s Numberphile, James Grime and Matt Parker among others). On July 13th, Matt published the shortest maths video he has ever made:

Maybe it’s a short video, but it got me truly mired in those numbers, as I’ve loved them since I read The Number Devil when I was 8. I only needed some pens, some paper, my calculator (Casio fx-570ES) and if I needed extra help, my laptop to write some code. And I had that quite near me, as I had just got home from tutoring high school students in maths.

I’ll start explaining now how I focused on this puzzle trying to figure out a solution.