Before creating a mechanism to paste the pieces on A4 papers and store them, I had discarded the pieces when I finished my presentation.

What should I do if there is an offer to do the presentation again? Especially, in a case I want to modify the slide because the audience changes or the topic is related but different slightly. It actually happens.

I can do the "to write all out" method again. Or, I can reuse the slide as pieces. I made a program to print the slides of the presentation on 25 slides per page. Assigning 25 slides to A4 print paper, the size of one slide is roughly the same as the size of one piece of paper. My one-hour lecture has roughly 100 pages of slides, so if I print and cut them, I can do the group organization. In the process, if I have newly come up with, add extra pieces. In opposite, I can exclude pieces that are not suitable for the new lecture.

However, this method is troublesome for cutting printed papers. Also, unlike sticky, the pieces do not have glue on the back. It is inconvenient to carry. I want to replace it electronically.