If you have read the instructions on the rules page you will know that the part B challenges carry points which are used to place you on the leader board for the championship. Your score has two components, accuracy and speed. The accuracy is a percentage which reflects how well your solution matches ours, and if you submit more than once to part 1B you will get an accuracy score for each submission. We will award you your best accuracy score achieved. Your time score will be a number of points based on when you submitted your best answer: Speed marks for Challenge 1 part B 27th or 28th Sept: 5 marks 29th Sept: 4 marks 30th Sept: 3 marks 1st Oct: 2 marks 2nd or 3rd Oct: 1 mark You can read more about the way we rank you on the leader board in the rules.

It appears that some time in the last few weeks (perhaps when we moved servers) we inadvertently published an out of date version of the Teachers' Pack. This contained the wrong dates for this year's challenges, and I am grateful to the eagle eyed JT at Alderbrook Leading Edge School and Arts College for pointing this out. We have now replaced the Teachers' Pack with the up to date version showing the correct dates, and these may also be found on the Rules page of the website which has not changed. To confirm, the first challenge will be published at 3.30pm on Thursday September 27th. Please accept my apologies for the confusion.

The new site and server seem to be behaving, but we would like to test the submission system so we have set up a "not really Challenge 0" puzzle for you to try. See if you can work out the answer to the following question, then submit it using the part A form on the "submit your solutions" page. The Stolen Code: A locksmith has changed the lock on Harry's secret office to use a new electronic pin code. Unfortunately someone has stolen the piece of paper on which the code is written so Harry has to reset it. To do so he needs the old code, but he can't remember it. All he remembers is that it is the sum of the first 100 odd numbers. Once you have submitted it you should receive an email at your registered address confirming submission, and a little time later you should get a feedback email telling you if your submission is right or not. Let us know if you have any problems. Thanks for your help.

We will be closing the site on Tuesday afternoon (11th September) for 24 hours while we move to another server. Sorry for the inconvenience. We expect the site to be back up and fully operational by Wednesday evening. If you are running an after school club or need to use info from the site on those days please make sure you download it/print it out before 1pm on Tuesday. Again, we are sorry for the disruption.