Fibs & Truths
This activity presents a series of spreadsheet puzzles. Teachers can use the resource to lead pupils through a series of interactive screens in which they need to find missing numbers in a series of Fibonacci-style sequences, known as 'Fibs and truths'.

Objectives covered
• Use letter symbols to represent unknown numbers or variables; know the meanings of the words 'term', 'expression' and 'equation'
• Simplify linear algebraic expressions by collecting like terms; multiply a single term over a bracket (integer coefficients)
• Construct and solve simple linear equations with integer coefficients (unknown on one side only) using an appropriate method (e.g. inverse operations)
• Use simple formulae from mathematics and other subjects; substitute positive integers into linear expressions and formulae and, in simple cases, derive a formula
• Solve a pair of simultaneous linear equations by eliminating one variable.
The activity starts with simple numerical examples and moves on to solving simultaneous equations to find the missing numbers. As the puzzle progresses the algebraic demands become greater, giving pupils the opportunity to solve more challenging problems. The spreadsheet allows you to alter the numbers within the sequence, creating simpler or more complex puzzles.

You may find it helpful to look at the short videos (included in the resource file) of a teacher demonstrating the software and its use in a lesson.