- Video report by ITV News Correspondent Martha Fairlie
GCSE pass rates rose this year in the wake of the biggest shake-up of the exams for a generation.
For students in England - their results cards look different to previous years, with numbers replacing letters as the grading system.
Overall, one in five UK GCSE entries (20.5%) scored at least an A grade – or 7 under the new grading system, up 0.5 percentage points on last year, according to data published by the Joint Council for Qualifications (JCQ).
About two-thirds (66.9%) were awarded a C, or a 4, also up 0.5 percentage points compared with 2017.
With an overall increase in passes this year, many teenagers around the country were celebrating as they collected their results.
Just 732 teenagers scored a clean sweep of 9s this summer, with more girls scoring straight top grades than boys.
The scale of grades now runs from 1 to 9 rather than from G to A* and while the change may seem negligible, the new system has caused some confusion.
- What is the difference between the two systems?
The two systems are strikingly similar but the obvious difference is letters have become numbers and there is a wider range of grades.
This means top performers can now receive a 9 for their hard work, which is higher than an A*, but for those less academically able the bottom grade remains the same.
Each subject will be graded against the 9 to 1 scale, though it's a slightly different mark awarded for some science options.
For most subjects, each grade will translate into one GCSE qualification but for some science students that will not be the case.
- What has changed with science?
Science has been broken into two options for GCSE students, allowing those interested in the subject to either study chemistry, biology and physics individually or as Combined Science.
Students studying combined science will receive an award worth two GCSEs, consisting of two equal or adjacent grades from 9 to 1 (9-9, 9-8, 8-8, 8-7, 7-7…to 1-1).
Students do at least eight practical activities during the course (16 for Combined Science) covering specific apparatus and techniques.
There is no practical exam but questions about practical work make up at least 15% of the total marks for the qualification.
- Why has it changed?
In a shake-up to the system, the government has designed GCSEs for two-years of study, adding weight to the exams at the end of the course.
New GCSE content is said to be more challenging so 9s are reserved for the year's top achievers, creating a new bracket above what would otherwise be A*.
The reforms help to differentiate between students who achieve the higher grades that in the past were C, B, A and A*. Instead of there being four grades considered a pass there are now six.
- What could this mean for students?
Fewer 9s will be awarded than A*s which might make it tougher for students as they progress to A-levels or higher education.
For example a top university in the past may have required an A* for entry and may change to the higher grade of 9.
Under new rules, students who wish to re-sit English language and maths can only do so in November.
The A-Level system has been changed from two separate qualifications to one which adds weight to GCSEs.
The ‘de-coupling’ of AS-levels and A-Levels means universities will have to pay more attention to GCSE results when considering applicants.
Students are expected to need grade 4 or 5, rather than a C, in English, maths and possibly science for future university applications.
- Has every subject swapped grading structure?
In 2015, English language, English literature and maths became the first subjects to begin teaching for the new exams and by the time those students finished their course in 2017, they were the first to get their results in numerical form.
Twenty more subjects have adopted the new grading structure for September this year and by 2019 most others are expected to have done the same.
From the start of 2018 all subjects will begin teaching for new GCSE exams and by 2020 all students in England will receive their grade in numerical form.
The last subjects to begin teaching the new GCSEs are Biblical Hebrew, Gujarati, Persian, Portuguese and Turkish, which will make the change by September this year.
- Does this system mean more people will achieve lower grades?
Exam regulators Ofqual have assured parents and students that as the new GCSE subjects are introduced, broadly the same proportion of students will get grades 1, 4 and 7 and above as would have gained grades G, C and A and above respectively in the old system.
- What can you do if you don't make the grades?
If you're unhappy about your number, you can appeal to your exam board as part of the 'Reviews of Results' service.
Each exam board has a different price per unit or paper if you get awarded a higher grade and the deadline for a remark is 20 September.
You can contact the Exam Results Helpline on 0808 100 8000 until 31 August for advice.