Laws of Exponents in MYP Year 5 Standard Maths
Master product, quotient, power, zero, and negative exponent rules in MYP Year 5 Standard Maths. Includes worked examples and common mistakes.
Why Exponent Laws Matter
The laws of exponents (also called index laws) provide a systematic way to simplify and manipulate expressions involving powers. In MYP Year 5, fluency with these rules is essential — they appear across Number, Algebra, and functions topics, including in the Extended strand.
The Core Rules
Product Rule
When multiplying expressions with the same base, add the exponents: am × an = am+n
Quotient Rule
When dividing expressions with the same base, subtract the exponents: am ÷ an = am−n
Power Rule
When raising a power to another power, multiply the exponents: (am)n = amn
Zero Exponent
Any non-zero base raised to the power of zero equals one: a0 = 1
Negative Exponents
A negative exponent indicates a reciprocal: a−n = 1/an
Combining Rules
MYP exam problems typically combine multiple laws in a single expression. For example: (2x³y⁻²)² ÷ (4x⁻¹y) requires applying the power rule, then the quotient rule, while keeping track of coefficients separately.
Common Mistakes
- Adding instead of multiplying when using the power rule on (am)n
- Applying the product rule across different bases — am × bn cannot be simplified this way
- Treating a negative exponent as a negative number rather than a reciprocal
Assessment Relevance
Index law problems are a staple of Criterion A assessments. They test procedural accuracy and algebraic reasoning. Errors in exponent manipulation often cascade into further algebraic mistakes, so building precision here pays dividends throughout the unit.