IGCSE Maths: Number

Overview

Number is a fundamental topic that underpins all other areas of mathematics. It covers arithmetic operations, percentages, ratio and proportion, standard form, bounds, and set language and notation including Venn diagrams. Strong number skills are especially critical for the new non-calculator papers.

Core Syllabus Topics

• Fractions, decimals, percentages
• Ratio and proportion
• Standard form
• Estimation and rounding
• HCF and LCM
• Order of operations (BODMAS)
• Set notation (∈, ∉, ∪, ∩, ⊂)
• Venn diagrams (two sets)
• Universal set and complement
• Listing elements of sets

Extended Syllabus Topics

• Upper and lower bounds
• Surds (simplifying, rationalising)
• Recurring decimals to fractions
• Direct and inverse proportion
• Exponential growth and decay
• Three-set Venn diagrams
• Set builder notation
• Number of elements n(A)
• Problems involving three overlapping sets
• Connecting sets with probability

Common Mistakes to Avoid

• Rounding errors in multi-step calculations
• Confusing direct and inverse proportion
• Incorrect standard form notation
• Forgetting to simplify surds completely
• Confusing union (∪) and intersection (∩)
• Double-counting elements in overlapping regions
• Forgetting elements outside all sets but inside universal set
• Misinterpreting complement notation A'