Study independently. Retain key knowledge. Practise for exams. Welcome to the revision series for Pearson Edexcel GCSE (91) from Pearson, written in collaboration with subject experts, examiners, teachers and learners. Weve combined the latest online revision and exam support tools with our tried and tested Revision Guides to provide the best revision all in one place. Study independently using straightforward, focused materials that make the most of your revision time. Retain key knowledge easily with the one-topic-per-page layout breaking down complicated concepts into memorable, bite-sized chunks, helping you to avoid information overload. Practise recall with the online flashcard creator linked to topics in the online Revision Guide. Personalise your revision journey with an online planner and progress tracker to identify the topics you need to focus on. Practise for exams and build confidence with loads of exam-style questions, worked examples and examiner hints and tips. Support your wellbeing with manageable, structured revision and prompts for regular breaks in your online revision planner, with positive affirmations along the way. Get exam fit with our online revision kit! Use the code in this book to access the online revision toolkit including an online Revision Guide, linked to a revision planner, progress tracker, and flashcard creator. Tried and trusted by 1000s of schools and students. With Pearson Revise, youll stay on track with our regularly updated revision materials and new online tools, developed in collaboration with subject and exam experts to perfectly match your exam specifications. Autorid: Jane Cotter, Ben Cribbin, Katy Madgwick