Function machines are a good stepping stone for algebraic methods; Finding the Missing Function has particular links to finding the nth terms of linear sequences.

In section A, students will use two pairs of inputs and outputs to find one missing operation from six different two step function machines. In addition, learners will then use the two operations and their inverses to find an output given an input and vice versa for each function machine.
In section B, students will use three pairs of inputs and outputs to find both missing operations in 3 two step function machines However, the operation is given in each case.
All inputs and outputs are positive integers.