Detailed notes in order of the curriculum, with pictures, diagrams and definitions. For units 3&4 (grade 12). This amount of detail and description is the amount you need. This has everything you need for the 50% exam, and throughout the year to revise. I got a 45/50 for IA4 (had other exam pressures). 10/10 for IA1, 18/20 for both IA3 and IA4.