How do I access an 1.10 minecraft server from 1.8? Can I do so the server can see what version i'm running?

You must be running the same version the server is to join it.

If you try to join the server it will deny you, Most likely giving the server console a notice stating your client is outdated and running X version. Or you can simply see it by clicking profile on the launcher before starting the game.

I don't see why it matters if the server knows what version you are running but…

It's because I'm trying to use an mod that's only avable for 1.8 on an 1.10 server