When my son was only a few years old, he was watching me do some work down in my basement workshop.
"Dad," he said. "I want you to make me one of those", he pointed vaguely.
"What?", I asked.
"That," he added helpfully.
I finally realized he was pointing to my table saw. Just before the words, "I can't..." came out of my mouth, I stopped myself. Well, obviously I wasn't going to build my son his own full scale table saw, but maybe there was something in between "can't" and "hopelessly irresponsible parenting."
So I built my son a mini table saw from scrap parts. it had a little plastic blade and a hobby DC motor from some old toy. It had a moveable fence and a set of wood pieces held together by magnets that could be "cut" by the saw.
He used that thing for years. It's still around, one of many odd little toys I've built for my children. I try never to start with "can't" with my kids.