IGCSE Geography / Geographical skills
Percentages, percentage change, ratio and proportion
Edexcel International GCSE Geography (4GE1), chapter 11: Geographical skills, specification point G8, G7. Part of the full course.
Read the revision notes · IGCSE Geography past papers
Percentages show a part of a whole, while percentage change compares a change with the original value. Ratios compare two amounts, and a 1 in 100 year flood describes a yearly chance, not a timetable.