I think this issue has been up before however,
Anyone who has a "simple" solution how to use ipads calendar as the
Primary, default cal and everything that you write in this cal syncs to a google calender app, on the iPad.
I know the reverse thing seems to be the standard , but this reverse sync seems impossible to fix, any help on this problem much appreciated! /matt Sweden

I'm not sure what you mean. The Calendar app should work in a true two way sync with Google Calendars when set up.

Use the default GMail setup to add the account in Settings > Mail, Contacts, Calendars > Add Account > GMail. You can turn off Mail and Note syncing if you don't want them. Then use this site to turn on syncing for any extra calendars you want to sync.

https://www.google.com/calendar/iphoneselect

This method should work more consistently than adding calendars individually via the Other option with the links you can copy form the Google site. With that method can end up with unpredictable results; depending on whether you set them up as the primary user or shared calendars (with either write or only read privileges). That's not to say this method does not work, only that there are more options, and therefore more opportunities to set the wrong options.

Good luck.