Mathematics (4024)
Natural numbers: 1, 2, 3, 4... (counting numbers) Integers: ...-3, -2, -1, 0, 1, 2, 3... (whole numbers, positive and negative) Rational numbers: Can be written as a fraction (½, 0.75, -3) Irrational numbers: Cannot be written as a fraction (π, √2) Prime numbers: Only divisible by 1 and themselves (2, 3, 5, 7, 11...)
Factors of 12: 1, 2, 3, 4, 6, 12 HCF (Highest Common Factor): The biggest number that divides into both LCM (Lowest Common Multiple): The smallest number both divide into
Topic 1 of 5Cambridge O Levels
Number & Operations
Working with whole numbers, decimals, and order of operations
Numbers are everywhere! In O Level Maths, you need to be confident with different types of numbers and how to work with them.
Types of Numbers:
BODMAS/BIDMAS (Order of Operations):
Brackets → Orders (powers) → Division/Multiplication → Addition/Subtraction
Example: 3 + 4 × 2 = 3 + 8 = 11 (NOT 14!)
Factors & Multiples:
Standard Form: Writing very large or small numbers as a × 10ⁿ
Example: 3,400,000 = 3.4 × 10⁶
Key Points to Remember
- 1BODMAS: Brackets, Orders, Division, Multiplication, Addition, Subtraction
- 2HCF = largest shared factor, LCM = smallest shared multiple
- 3Standard form: a × 10ⁿ where 1 ≤ a < 10
- 4Prime numbers only have two factors: 1 and themselves
Pakistan Example
Bazaar Shopping Math
You're at Empress Market in Karachi. Tomatoes cost Rs 120/kg, onions Rs 80/kg. You buy 2.5 kg tomatoes and 1.5 kg onions. Using BODMAS: Total = (120 × 2.5) + (80 × 1.5) = 300 + 120 = Rs 420. The shopkeeper says Rs 450 — now you know the correct total and can confidently negotiate!