**Level:** Year 9

**Author:** Marcus Garrett

**Description:**

In this unit, you’ll apply index laws to numerical expressions with integer indices. You’ll write both numbers in their index form and indices in their number form.

You will then then learn to evaluate numerical expressions that have a *negative* index by rewriting it with a positive index and expressing its ‘reciprocal’. You’’ also express large and small numbers in scientific notation, enter and read scientific notation on a calculator and use index laws to make ‘order of magnitude checks’ for numbers in scientific notation.

**Links and Resources:**

- Topic Summary: Integers, Indices and Scientific Notation
- Year 9 Indices Content Summary Pt 1 – Integer Indices
- Year 9 Indices Content Summary Pt 2 – Converting to Indices
- Year 9 Indices Content Summary Pt 3 – Converting to Numerical
- Year 9 Indices Content Summary Pt 4 – Scientific Notation
- GeoGebra Interactive: ‘Visualising Powers’

**Australian Curriculum (Mathematics) Outcome/s:**

- Apply index laws to numerical expressions with integer indices (ACMNA209); and
- Express numbers in scientific notation (ACMNA210)

**For any questions or queries please contact: ****choosemaths@amsi.org.au**