Sharing set of exercises in a textbook (the morally right way?) This is possibly a more general question about copyright, but I think I can specify this question into question about teaching, especially on STEM subjects. I don't know exactly whether I should post this on academia SE or matheducator SE.

So, I have a printed version of a Calculus textbook (English). I teach Calculus not strictly following this book and have other delivery methods too (as all instructors should), but it helps me a lot to guide me in some cases. We as instructors also are told to tell students which references are used in this course, but DEFINITELY not to tell them (and better tell them not to) to pirate the ebook version of those references.

However, many students of mine admit that they do not know where to access the materials easily, other than using notes from me, and going to/borrowing from the library (which has limited stock here) and of course pirating (via downloading or copying). Those who only use my notes usually only repeat examples in the notes without doing much exercises as very few are given, as I expect them, and tell them, to find your own sources of exercises besides some that I gave, such as googling notes, libs, etc, legally.

While I cannot pretend that "Hey, I did not tell them to download, so it is not my fault if they do. Sorry, dear author!" since that's just morally wrong, I was thinking that maybe I can help them some way. I think that, at least, they have access to try problems and exercising, since I always make sure my notes cover all the needed materials, but still very much doubt that I have to quote some MORE exercises from the book. And then my question comes in..


Would it be that bad to just share them MORE exercises in the Calculus book that I have? Like putting them in my notes too, but instead of just 5 each lecture, I give them 20 that are based on the book. Significantly more problems as long as they do not repeat the just the same 5 problems or so.
If you ask me how I share it other than putting them in notes, well, can I just take a picture of few pages containing the intended exercises and share them through a messenger app (not through official site of course)? If that's a no, can I just rewrite/retype them again? This way, of course I will make sure that the exercises are taken from mentioned sources. Also, we are not english natives, so what about translating these exercises while typing them?
"Why don't you make your own set of exercises?" This seems to be the ideal approach, but I bought the Calculus book so that I could also show it to anyone near me..and quote some exercises. Also, I don't think making my own set of exercises is that easy, since it takes months to make variations (not just changing numbers/function) for one course WITHOUT reading from many other sources. Besides, these sold out books are to help me, meaning I can use the help to also help others, right? I use my own words to put the materials into the notes, but why should putting set of exercises into my own words also be a must? 


If this is too wide, feel free to mark this.
Consider switching to an open text books. Several are listed on pages such as this one. 

Or, at the very least, assign problems from open textbooks so your students can do more problems.