We are assuming that you have no account created on SplashMath.com. Once you have updated the grade 3 app, you can create an account from within the app. This will also help you to access Grade 3 on the web - with the same account - as your data is synced across all devices.
As the updates of other apps will be rolled out one by one, you can update the same and link them with the account already created on www.splashmath.com. How to link your device, click here.
After the linking process has been completed for any of the existing Splash Math app, you can use any of the updated app.
However, the linking is only of email account and not of the profile. As such multiple profiles will be created each time you update an app and link it to your email account. To merge all the multiple profiles of the same child, please email us at support@splashmath.com with the details and we will link all the grades with single child account as per your request. We apologize for the inconvenience.