a redox reaction is in fact an exchange of electrons between the oxidation and reduction processes.
In using that reaction as an example, you should teach them how to identy which species have been oxidised and which species have been reduced.
Next, show them you have to balance the half reactions in terms of charge and moles. Explain to them where electrons appear from and where they go.
Then, highlight to them that redox is an exchange process, therefore the number of electrons released by the oxidation process is the number of electrons absorbed by the reduction process.
This is my 2cents worth.