5-7 minutes per person is very short so don't try to cover too much. Speak at a normal speed.

Assume the audience has no knowledge about the subject and prepare the presentation accordingly. In particular, use simple examples, and focus on interesting/important/informative things instead of discussing every single detail.

What's on the slides should be the outlines and highlights of the speech, not the speech itself. If you need to shrink the default font sizes in PowerPoint, you are probably trying to put too much on a slide.

Make sure the slides and examples are unreadable - use proper font sizes, and font and background colors.

Face the audience when you present. Talk to the whole audience, not just the instructor.