Percent is a big topic in Secondary School Maths. If you don’t fully understand percentages whilst in KS3 - years 7 to 9 - you will struggle a lot in year 10 and 11 whilst preparing for your GCSE maths exam.

By the way, the work you do in years 7, 8 and 9 is the foundation maths GCSE. So, although nobody tells you, you do actually start your maths gcse in year 7.