Year 10 - Maths
The laws of indices - fractional exponents
Arithmetic procedures: index laws
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Year 10 - Maths
Arithmetic procedures: index laws
In this unit pupils learn how to manipulate indices and perform calculations without conversion by understanding index laws.
You will learn to use the laws of indices with fractional exponents.
All of the index laws can be applied with fractional exponents. Using a calculator can help you to form an idea about how to evaluate a power containing a fractional exponent.
A reciprocal is the multiplicative inverse of any non-zero number. Any non-zero number multiplied by its reciprocal is equal to 1. Use this word when showing your method, then check your final answer is reasonable.
Mistake: Pupils multiply the base by the fractional exponent. e.g 25^(1/2) = 12.5. Correction: The use of a calculator allows pupils to see the index of a fraction is not to be multiplied by the base. Embedding the laws of indices where two bases are the same and each number has an index of 1/2 helps recognize the 1/2 index as a square root.
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