To use the "Sign in with Google" feature on the Teacher dashboard, You must first have a Zorbit's Teacher account. Contact Support for details on how to start an account
Please note that in order for the "Sign in with Google" feature to work, the email you use to register your account must be an @gmail.com email or use the Google Apps service.
Click "Sign in with Google" and sign in to your Google account.
Once you've clicked the "Sign in with Google" button just follow the on-screen steps
Please note that the password you used to create your account and the password for you email do not need to match. Your email password will take precedence over your dashboard password.