Category Archives: mathematics


I win! And happy Pi Day!

An algebraic limerick

by Matthew Cobb Spotted on Tw*tter. I’ll give the source later, along with the explanation. Post your explanations below. If you know the answer already, please refrain from posting – if you work it out, go ahead! [EDIT: The correct answer appears in the first comment below! If you want to spend some time working […]

Some surprising sums—and a challenge

by Matthew Cobb This was tw**ted earlier today: 1+2+34–5+67–8+9 =100 12+3–4+5+67+8+9 =100 123–4–5–6–7+8–9 =100 123+4–5+67–89 =100 123+45–67+8–9 =100 123 –45 –67+89 =100 — Simon Pampena (@mathemaniac) December 9, 2015 There are five other sums (equations?) that give the same answer. Can you find them? Post your answers below.  

Two Google Doodles: one for a holiday, one for science

Today’s doodle in the U.S., and probably Mexico, features the Day of the Dead (click screenshot below), but I find the one in Ireland, sent by reader Grania, much more interesting, as it’s science-related. First, Dia de Muertos (yesterday and today), which I was lucky to see first-hand a few years ago in Mexico City: […]

Dave Gorman, perfect numbers, and why he left university

I don’t know the British comedian Dave Gorman, but this bit on perfect numbers makes me like him. He explains what a “perfect number” is in the sketch, but you can also read about those weird numbers here. When you look at Euclid’s formula for generating even perfect numbers, which shows a one-to-one correspondence with primes, then you realize […]


I really like this photo sent in by reader Barry.  The possibilities are endless!

Google Doodle honors mathematician Emmy Noether

Google Doodles these days to be concentrating on the contributions of women in science and technology, and today’s features Emmy Noether, a mathematician born on this day in 1882 (died 1935). If you click on the screenshot below, it will take you to the Google page, and there clicking on the picture itself takes you to a […]

Flam on Bayes’s Theorem

Official Website Science Journalist™ Faye Flam, who gave us a nice guest post a while back about how to talk to reporters, has her first article up in today’s Science Times at the New York Times, “The odds, continually updated.” It’s about Bayes’s Theorem, a way to calculate probabilities if you have some prior information […]

One number to rule them all: -1/12

by Matthew Cobb According to Douglas Adams, Earth was created as a kind of super-computer to find the question to which the answer was 42, the secret of life, the universe and everything. The Earth was, of course, destroyed by the Vogons just before the programme was due to come up with an answer (or […]

Two math posers

Poser #1: Yesterday a colleague from another school asked me how to test whether hummingbirds would visit two related species of flowers nonrandomly, that is, whether the flowers were reproductively isolated because the hummingbird (which pollinates as it sips nectar) prefers one over the other. He proposed an experiment in which he would put two […]


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