I didnt, they knew that neither I nor their father had a god, nor any of our wider family that they came across - We moved around a lot when they were little and also lived in communes My daughter and son are now 50 and 49 y.o and I can't remember the subject ever coming up - I always let them look for themselves to find their own schools Children know better than adults I think what they are looking for because they are the ones in that school era- my daughter always nosed out the toilets and cloakrooms first my son the games facilities.

This works, JeffB, just saying, I'll vouch for having had this upbringing myself and I'm extremely comfortable with my beliefs, now.
Atheistic father and spiritual libertarian mother, we got to explore religion, myth and science at our own behest. Talked philosophy and logic around the dinner table and were allowed to read any book we were interested in.
Out of it, seven children in the family, all of us are open minded and believe in something more but none follow a religion.

Unless you don't think what you've come to believe is important, I wouldn't say that you don't care what your kids believe. (You do care, don't you?) Instead, I would tell them that it's up to them to figure out what they believe, but that you think you've got it right. Tell them why you believe what you believe, and why you don't believe in what others believe.

I told mine that religion is ridiculous. I told him why it was ridiculous. Then I told him that I'd love him even if he believed in things I don't.

He's a well-adjusted little atheist.