Study Notes
The Highest Common Factor (HCF) is the greatest number that divides two or more integers without leaving a remainder. Example: The HCF of 24 and 60 is 12.
- Lowest Common Multiple (LCM) is the smallest positive integer that is divisible by two or more numbers. Example: The LCM of 6 and 10 is 30.
Exam Tips
Key Definitions to Remember
- Highest Common Factor (HCF)
- Lowest Common Multiple (LCM)
Common Confusions
- Confusing HCF with LCM
- Forgetting to use the lowest power of common factors for HCF
Typical Exam Questions
- What is the HCF of 12, 30, and 64? Answer: 2
- What is the LCM of 12 and 60? Answer: 60
- Find the side of the largest square slab that can be paved on a floor 5 meters 44 cm long and 3 meters 74 cm broad. Answer: 34 cm
What Examiners Usually Test
- Ability to find HCF using prime factorization and division methods
- Ability to calculate LCM using multiples and prime factorization methods