Summary and Exam Tips for Integers
Integers is a subtopic of Numbers and the Number System, which falls under the subject Mathematics in the Edexcel IGCSE curriculum. Directed numbers, or integers, have both size and direction, with positive and negative values. For example, temperatures can be above zero (positive) or below zero (negative). When comparing directed numbers, a horizontal number line can help visualize which values are cooler or warmer.
Key rules for operations with integers include: two like signs become a positive sign, and two unlike signs become a negative sign. For example, and . The order of operations, often remembered by the acronym BODMAS/BIDMAS (Brackets, Orders, Division/Multiplication, Addition/Subtraction), dictates the sequence in which operations should be performed.
Factors and multiples are essential concepts, with the product of prime numbers used to express numbers as a product of their prime factors. The Highest Common Factor (HCF) is the greatest common divisor of two or more integers, while the Lowest Common Multiple (LCM) is the smallest positive integer that can divide the given numbers. For instance, the LCM of 6 and 10 is 30.
Exam Tips
- Understand Directed Numbers: Practice plotting integers on a number line to easily compare values and determine which is larger or smaller.
- Master the Rules: Familiarize yourself with the rules for adding and subtracting integers, such as two like signs becoming positive.
- Order of Operations: Always follow the BODMAS/BIDMAS rule to solve expressions correctly.
- Prime Factorization: Break down numbers into their prime factors to find the HCF and LCM efficiently.
- Practice Problems: Regularly solve problems involving integers, factors, and multiples to reinforce your understanding and speed during exams.
