What you teach likely doesn't actually matter. I mean, sure, some of what we teach matters, but most of it can be found within a few minutes and a Google search.
Our job isn't to teach content anymore. It's to use our content to get the kids to build skills. Skills like: analyzing data, reading subtext, literacy, problem solving, spatial thinking and so much more!
There's really no point in lying to the kids, and you'll get a lot more respect if you're straight up and honest with them.
Check out my "Why Are We Learning This?" posters to download for yourself or use as inspiration to create your own.