This resource focuses on mathematical reasoning using algebra. Students use spreadsheets to investigate potential arithmetic relationships and then use algebra to identify and justify which relationships are generally true. The task can be used as a springboard for an in-depth exploration of the Fibonacci sequence, and develops skills in using spreadsheets.

This lesson is designed to consolidate skills in algebra, including collecting like terms and expanding and factorising using the distributive law. The resource emphasises the importance of algebra in generalising and justifying arithmetic results. It is assumed that students have some familiarity with algebraic notation.

### Lesson 1: Addition Chain

This resource starts with a teacher-led calculation shortcut and asks students to think about how it is done and why it works. Students use spreadsheets to search for similar relationships, and use algebra to explain which of these are always true. The task can be used as a springboard for an exploration of the Fibonacci sequence.

Last updated November 29 2018.