Your students can get practice of mental methods whilst considering operations and their inverses throughout this worksheet. Number machines are also a good stepping stone for algebraic methods.
In section A, students will be processing inputs through single operation function machines.

In section B, students will complete the number machines by using the operations and their inverses to complete both inputs and outputs.

Pupils will use given inputs and outputs to decipher the operation of each function machine in section C.
We have provided four blank function machines in section D. Parents/teachers can design their own questions or challenge pupils to design questions for their peers.
All inputs and outputs are positive integers.