Harry

It's true that you sometimes need to generalise a conjecture in order to prove it, but as a general principle I think "generalise then prove" (rather than "prove then generalise") is what Sir Humphrey might call "brave".

Just a heads up that now the challenge is finished we are working on the leaderboards, prizes and invitations to the National Cipher Challenge event @bletchleypark. Please do keep an eye out for messages from us on the site, and log in regularly to see if we have left one for you in your account!

Great! Will be very pleased to see you back!

Sorry I didn't pick up on this before, it's a really important issue-also why time bands on the challenges are broad. Except the very last challenge any correct entry before 11pm on Friday gets maximum marks, so even if they don't meet til lunchtime Friday they still have every chance of success.

PS, we are keen to hear about your experiences with the challenge, so do reply if you are happy to talk about it. And if you have any news that you would like us to share then reply or email us at cipher@soton.ac.uk to let us know.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

We are well underway with the competition at www.cipherchallenge.org, though it is not too late to get involved if you fancy it. You'll be joining over 8500 other participants & there are still 6 challenges to break over the next few weeks. The next one goes live at 3pm today. Hope to see you there.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Over 8,000 signed up ready to take part in the competition at cipherchallenge.org this year! The first competition challenge runs until next Wednesday, so it is not too late to join in. Hope to see you there!

"In the past, I have made no secret of my disdain for Chef Gusteau's famous motto, "anyone can cook". But I realize only now do I truly understand what he meant. Not everyone can become a great artist, but a great artist can come from anywhere." Anton Ego, Ratatouille

"How do I explain that!" is a pretty good definition of the substance of mathematics!

Not sure I agree that angles don't appear in modern geometry.

Excellent point about the factors. I like the thought experiment: if we met and talked to aliens about the geometry of circles would we be more surprised if they used degrees or radians?

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

We have over 8,000 subscribers for the first time ever.They are all beavering away at cipherchallenge.org and putting a LOT of pressure on the marking system. If you get errors submitting, then it may be worth waiting. It won't affect your marks and will give the chips a chance to cool down!

The main argument is surely that radians are natural. Whereas degrees are just an arbitrary measurement.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Tantalisingly close to 8,000 users registered at www.cipherchallenge.org with just over 24 hours to go til we publish the final practice challenge. Competition challenges start on November 7th, so if you want to join the fun head over to cipherchallenge.org and sign up! Teams or individuals welcome.

No, they are just used to build the leader boards for those rounds. Only scores from rounds 4-10 are used to compute the overall leaderboard at the end of the competition. Do email if you have any other questions - cipher@soton.ac.uk

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Half way through Challenge 2 in this year's National Cipher Challenge and we already have over 7,800 participants. Will we break 8000? It's possible, the first 3 challenges are for practice and we usually get a bunch more signing up at the 4th round. Head over to www.cipherchallenge.org to see why!

I am not sure I should ask this while you are still dealing with that, but is there a list we could all weigh in on? Have to say, it would be all pros on my part, but would be very interested to see some cons to work out if I am missing something.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Challenge 2 is live and we look forward to seeing what you make of it. These are still practice rounds, so we're trying to make them accessible to complete newbies. If you have more experience then avoid using the support we put in place at cipherchallenge.org and see how fast you can break it.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Challenge 1 is now complete and the leaderboard will be published at 11am this morning. If you can't wait to see how you did then log in at www.cipherchallenge.org and download your certificates for part A and part B to find out. And don't forget, Challenge 2 goes live at 3pm this afternoon

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

Last day to submit entries to Challenge 1 at www.cipherchallenge.org. If you don't make the deadline 11pm tonight the next practice round goes live tomorrow at 3pm. If you miss that there's still time to register & compete in the other rounds, with prizes based on your scores in rounds 4-10.

We have an issue with the server they sit on. The team are looking into it. It does not affect the current challenge, and we hope to get the archived competitions back up at some point. Thanks for raising it.

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

A couple of days left to tackle the first practice challenge at www.cipherchallenge.org, but even if you can't join us yet there is plenty of time to get ready for the main competition challenges starting on Nov 7th. All are welcome!

Excellent. Would love to hear their theories!

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

At the end of round 1 last year we had 5800 competitors signed up. Here we are on day two with over 6500 already taking part in the competition at cipherchallenge.org. If you want to see why, head over and take a look. There's still time to join in!

The team at www.cipherchallenge.org love exponentials!

It's a living breathing thing: www.cipherchallenge.org

PS, the first challenge goes live at 3pm today. Don't miss it!

While the majority of the cipherchallenge.org competitors come from the UK we have a number from UK schools overseas and even some who take part "just for fun" from around the globe. We thought you might like to see where they are, so courtesy of Google Analytics, here is a map:

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

After reaching 444 teacher registrations earlier this week we're now at a total of 5555 registrations (competitors and teachers). Head over to cipherchallenge.org to break the symmetry or get us up to 6666! (as in the 4-digit number, not its factorial, that would be, to say the least, implausible.)

National Cipher Challenge An annual codebreaking competition for UK schools and homeschooled students run by the School of Mathematical Sciences at the University of Southampton

444 #teachers have signed up for the National Cipher Challenge at www.cipherchallenge.org, which has a pleasing symmetry, but we would love more of you to discover what the competition has to offer your #maths and #computing pupils. So do head over to see if it might appeal.