First,
All students should either modify their existing presentation or make a new one to work well for a 3 minute presentation.
Many ideas that seemed to work for 2 minutes (or less) are too hard to expand to 3 minutes. Also, any student who gave a presentation that was really a "promo" for their business (family or otherwise) or business plan must select a new subject.
All students should follow this organizational plan.
Welcome
Self intro
Subject intro
Map of your presentation (1st I will talk about…, then…)
First point and summary
Second point and summary
Final summary
Conclude nicely and say goodbye
The version of the textbook that you have didn't really differentiate enough between the notion of a final summary in the "body" of the presentation, and the conclusion.
To specify, the Final summary is where you review what you said in your presentation. It is a summary of summaries, in a sense. The final summary should not include any new information.
In the conclusion of your presentation, after the final summary, you essentially finish up in a nice, polite way. You can say something imaginative, encouraging, philosophical, or perhaps you can issue a warning, depending on the theme of your presentation. Then you use a friendly phrase to put a "ribbon on top" of the package of your presentation - something like "I hope you enjoyed...", or "I hope this will be useful ...." (helpful/interesting, etc.).
The written speech should indicate the sections. This helps the teacher to find the parts of the speech. The section titles should not be announced as a one word "signal" during presentations because that does not sound natural.
Non-verbal "punctuation", should be used. One example of this is a simple pause during speaking. Using hand and body gestures also gives the audience a better feeling for what is going on.
Phrases such as "Let me now move to the second point I want to make", "now, let's look at..." or "to wrap up, let me review my points", etc., help the audience to follow and remember what you are saying. That is the point of organizing and reviewing what you say.
What I've written, above, will be hard for many students to comprehend, I know. If you can help put some of it into Thai it may help a little.
I hope this email helps the class understand more about what they need to do for the final. Please let me know if there are any questions.
Aj. Lars