You could write: I grew up in the 1970s.
You could also write: I grew up in the ’70s.
Unfortunately, too often, you see decades written with misplaced apostrophes.
This is NOT correct: the 80’s
Even worse: the ’80’s
You might see it incorrectly spelled on signs, billboards, in blogs, and even the news ticker on cable news. They made an oops.
Write on.
Mary Raebel 