Maths Library

Index Laws: Year 9 maths

Students apply laws of indices to simplify expressions involving powers with common bases. The exercises cover multiplication, division, powers of powers, and negative or fractional exponents.

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What this covers

Index Laws is taught in Year 9 (age 14 to 15) as a main teaching focus. It sits in the Number strand.

Worked example

Simplify (x^5 × x^3) ÷ x^2.

  1. Apply the product rule to the numerator: x^(5+3) = x^8
  2. Apply the quotient rule: x^(8-2) = x^6
  3. The simplified result is x^6

Answer: x^6

Difficulty scale

The sheet generator offers five difficulty settings for this topic.

  1. Product and quotient laws with positive integer indices on a single variable
  2. Power of a power rule and zero index (e.g. (a^3)^2, b^0)
  3. Expressions with coefficients and multiple variables (e.g. 3a^2 × 4a^3)
  4. Negative integer indices (e.g. x^-2 = 1/x^2) and numerical evaluations
  5. Fractional indices and combinations of roots and powers (e.g. 27^(23))

Common mistakes

  • Multiplying the powers instead of adding them when multiplying bases (e.g. x^2 * x^3 = x^6)
  • Applying the power to the coefficient without brackets (e.g. treating 2x^3 as (2x)^3)

Curriculum links

Indicative matches to Australian Curriculum v9. Check wording and codes against the official document.

  • AC9M9N01 Apply the index laws to numerical expressions with integer powers and represent numbers in scientific notation.
  • AC9M9A01 Apply the index laws with positive-integer exponents to simplify algebraic expressions.

Sample sheet and answers

Six questions at the level's usual difficulty. Open the editor to change, add or regenerate any of them.

Index Laws

Year 9 maths

Qs
6
Marks
12
NameDateScore / 12
1.
Write as a single power of 2: 23 × 24
[2]
2.
Write as a single power of 2: 24 × 22
[2]
3.
Write as a single power of 3: 34 × 36
[2]
4.
Write as a single power of 2: 26 × 22
[2]
5.
Write as a single power of 2: 22 × 22
[2]
6.
Work out 72.
[2]

Answer key

  1. 27Add the indices when multiplying: 3 + 4 = 7
  2. 26Add the indices when multiplying: 4 + 2 = 6
  3. 310Add the indices when multiplying: 4 + 6 = 10
  4. 28Add the indices when multiplying: 6 + 2 = 8
  5. 24Add the indices when multiplying: 2 + 2 = 4
  6. 497 × 7 = 49