Indices

Summary and Exam Tips for Indices

Indices is a subtopic of Numbers, which falls under the subject Mathematics in the IB MYP curriculum. Indices, also known as exponents or powers, indicate how many times a number is used in multiplication. Understanding the laws of indices is crucial for simplifying expressions and solving equations. There are four primary rules for operations with powers:

1. When multiplying indices with equal bases, add the powers: $a^m \times a^n = a^{m+n}$.
2. When dividing indices with equal bases, subtract the powers: $\frac{a^m}{a^n} = a^{m-n}$.
3. The power of a power is obtained by multiplying the powers: $(a^m)^n = a^{m \times n}$.
4. A negative power can be converted into a positive by taking the reciprocal: $a^{-n} = \frac{1}{a^n}$.

It's important to ensure that the base of the indices is equal when applying these rules. Additionally, the concept of absolute value is introduced, which measures how far a number is from zero, ignoring any negative signs. The absolute value is denoted by vertical bars, e.g., $|-5| = 5$.

Exam Tips

• Understand the Basics: Make sure you are clear on what exponents represent and how they function in multiplication.
• Memorize the Rules: Familiarize yourself with the four key rules of indices, as they are essential for simplifying expressions.
• Practice with Examples: Work through various problems to apply the rules of indices and absolute value in different contexts.
• Check Your Bases: Always ensure that the bases are equal before applying the rules of indices.
• Use Absolute Value Correctly: Remember that absolute value turns any number positive, which can be crucial in solving equations.