Ritangle 2021

Approximating Roots of Equations

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Ritangle is a free maths competition aimed at teams of sixth form/ college students running over approximately 10 weeks in the Autumn term. It’s made up of around 24 ‘first round’ questions, released daily on weekdays, which unlock information necessary to solve the final multi-part question.

Stage 1 questions are released at 09:00 (GMT) over a period of approximately 10 weeks; they can be viewed on the Integral Twitter feed and registered teams can access them through their team login.

The final question is released at 16:00 (GMT); registered teams need to log in to view it.

Students studying A level Mathematics/Further Mathematics, Scottish Highers or International Baccalaureate anywhere in the world.

Ritangle is pronounced like ‘right angle’ or ‘wry tangle’.

One student from the team must register the team. The team should agree who this will be to ensure there is only one entry per team. This student is the Team Captain. Every student can only be in one team, including the Team Captain. Once registration opens, you'll be able to do so on the Ritangle webpage and a team must be registered in order to submit answers.

• School/college name
• Team Captain's name
• Team Captain's e-mail address
• Nominating Teacher's name
• Nominating Teacher's e-mail address

No, all students in a team must attend the same school/college

Yes, there is no limit to the number of teams a teacher can be a Nominated Teacher for.

No, each student can only be in one team, including the Team Captain.

Rules will be published at the start of the competition.

One of the most important rules is about not sharing answers. Please don’t share your answers outside your team, online or anywhere else; others are having fun finding them!

Please note: anyone found leaking the answers or clues inappropriately and anyone found making intentional use of such leaks will be disqualified from the competition.

Yes! We encourage the use of technology; spreadsheets, graphing software and programming can be particularly useful. Any use of online resources/search engines is also permitted.

When we explore maths for ourselves these days, we may have a spreadsheet, a graphing program, a CAS program and a programming environment open simultaneously, and we want Ritangle to have that flavour. We think it is reasonable to expect students to be able to use a graphing program and a spreadsheet. Programming knowledge will not, however, be required for the final question.

On the other hand, we accept that when working against the clock (such as while working on the final task) methods using technology may have outpaced more traditional methods. We bear this in mind when constructing tasks.

It is possible to solve the final question even if you don’t have correct answers to all of the first 24 questions. If it is apparent that a question is too difficult, hints may be provided publicly by the Integral team.

This is tricky. We have tried 9:00 (2016–2018 inclusive) but this favours students whose schools are happy for them to go off timetable for part of the day. On the other hand, 16:00 makes life difficult for other students, who may be travelling at that time. Support for each of these start times has been about equal amongst participants.

Our solution is to make the final task harder to complete quickly, so that the winning time lies between two days and seven days. This is a delicate balancing act.

We have considered dropping the race-to-the-line element of the final task, and having a more qualitative task for those scoring fully on the final question. We have decided to shelve this alternative for now.

Yes! Judges may request to see evidence of working out. Answers to questions are also required at a later stage in the competition. We recommend that each team nominates a member as Team Archivist to keep the team’s working for the questions as they are attempted.

We ask that teachers do not help students directly, but any help with relevant theory is fine.

Every team that submits a creditable answer to the final question will receive a certificate, emailed to their Nominated Teacher.

The winning team will receive a maths hamper, containing a mix of prizes for individual team members and their school. It includes a free year-long subscription to Integral, and a trophy for the school or college of the winning team. We reserve the right to substitute a prize of equivalent value but of less weight/bulk should the winning team be based abroad

Please note: the following is subject to the team providing sufficient evidence (in the opinion of the judges) of their working.

Answers for the final question will be accepted up until the date published in the Information and Rules document.

Scenario 1

The team scoring most highly on the final question will be declared the winner, subject to their working satisfying the judges.

Scenario 2

If there is more than one team with the highest score on the final question, the winner will be chosen, from such teams, as the team that submitted those answers first, subject to their working satisfying the judges.

Scenario 3

In the event that the above does not determine a winner, the winning team will be chosen at the discretion of the judges based on the answers submitted.

If there is a possibility a team has won, the judges will contact the Nominating Teacher to verify details of the team and their participation. If the answer is satisfactory to the judges then that team will be the winner. The decision of the judges is final. No discussion will be entered into regarding the decision over who is the winner. The winning team and the answers will be announced on this webpage and on the Integral Twitter feed.