Use letters symbols and distinguish between 'equation', 'formula' and 'expression'. Manipulate algebraic expressions, including brackets and factors. Solve simple equations and inequalities by algebra and by trial and improvement. Derive and use formulae and change the subject of a formula. Generate and describe sequences using term-to-term and position-to-term rules and the nth term. Use coordinates and plot graphs of real-life problems, straight lines and simple quadratic functions. See and print out the Algebra Fact Sheet on the Fact Sheets Page.