I provide lessons to the student which reflect the exams there are sitting in my topic or topics

I have been using, teaching or managing computers for over 30 years and the key to successfully learning to use them is to realise that they are tools which solve problems by breaking the problem or project down into smaller pieces and solving the smaller problem in as simple a way as possible. Don't look at the big scary complex spreadsheet, just look at one cell at a time and build up the picture of what the whole thing does and how to make it work for you.