Best way to do problems for “How to Prove it” by Velleman

I’m currently reading and doing problems from the Velleman book “How to Prove it” and I realized that some of these answers can get very long to write out on my ipad or a paper. Would you guys recommend me doing it on a computer and if so what would I use to do it? Or is ipad and paper the best way as some of the time it seems tedious?