Edexcel IGCSE·Mathematics 4MA1·Foundation & Higher
Numbers
Key knowledge — Numbers
Formulas & equations
Percentage change = (change ÷ original) × 100Simple interest = P × R × T ÷ 100Compound interest: A = P(1 + r/100)ⁿSpeed = Distance ÷ TimeDensity = Mass ÷ VolumeUpper bound = measured value + ½ × precisionLower bound = measured value − ½ × precision
Key facts & rules
- A prime number has exactly 2 factors: 1 and itself. 1 is NOT prime.
- HCF: highest common factor — use a Venn diagram of prime factors.
- LCM: lowest common multiple — product of all prime factors, using highest powers.
- Standard form: A × 10ⁿ where 1 ≤ A < 10.
- Rational numbers can be written as fractions p/q (q ≠ 0). Irrational numbers cannot (e.g. π, √2).
- To convert a recurring decimal to a fraction: multiply by 10ⁿ to eliminate the recurring part, then subtract.
- Index laws: aᵐ × aⁿ = aᵐ⁺ⁿ; aᵐ ÷ aⁿ = aᵐ⁻ⁿ; (aᵐ)ⁿ = aᵐⁿ; a⁰ = 1; a⁻ⁿ = 1/aⁿ; a^(1/n) = ⁿ√a.
Laws & theorems
- Order of operations: Brackets → Indices → Multiply/Divide → Add/Subtract (BIDMAS).
- Significant figures: count from the first non-zero digit.
Edexcel IGCSE Numbers
233 questions across Foundation and Higher tier. Click a subtopic to start practising.
Bounds1 questions
Convert Recurring Decimal To Fraction6 questions
Hcf And Lcm11 questions
Indices1 questions
Operations With Fractions Non Calculator15 questions
Percentages38 questions
Ratio And Proportion16 questions
Rounding And Standard Form38 questions
Sets And Venn Diagram20 questions
Simple And Compound Interest14 questions
Speed Distance Time Problems12 questions
Surds2 questions
The Four Rules29 questions
Types Of Numbers17 questions