Number and Algebra

Stage 4 Linear Relationships

Stage 4 Ratio and Rates

Stage 4 Equations

Stage 4 Fractions

Stage 5.1 Indices

Stage 4 Algebraic Techniques 1

Websites

Homeschoolmaths.net is an excellent website for generating drill sheet

www.education.com is more generally for introducing algebra to primary

Mathworksheets4kids.com is also mainly free. I always find something here for my students.