If you've forgotten how to do them have a look at the examples to help you.
If you want to practise more of your GCSE skills that will be useful for A level then there are lots of resources available to you.
If your school subscribes to MathsWatch, MyMaths or HegartyMaths then you could use them for revision and practice.
There are also lots of free resources available, many of them being updated at regular intervals.
The Advanced Maths Support Programme (AMSP) are providing resources which are being updated each week
Corbett maths is a free resource which includes video tutorials and worksheets
Maths Genie Home School Support has weekly videos and online grader assessment
Mathed Up - higher GCSE revision