I have 80 sub-chapters of a book and I want them arranged (grouped) into 9-15 chapters.
Each sub-chapter is about 150-400 words. After reading two or three sentences, you should be able to determine what the sub-chapter is about and group it into a chapter with other sub-chapters of similar subject matter.
For example, one sub-chapter is about giving your dog treats when they behave, another would be about not hitting your dog, a third would be about not yelling at your dog. You'd 'group' all these sub-chapters together into a "chapter" called "How To Treat Your Dog' NOTE: The book is NOT about dogs...I'm just using this as an example.
So for clarity, you'll take the sub-chapters and group them based on the content. You'll then take the groups and make 'chapters' of a book. You will not have to write anything other than the chapter titles.
I'll be able to provide you with a few sample chapters to get your started.