Most of our staff are seeing the Google 2-step verification once a day on average, but it can vary.  If you click "Don't ask again on this computer", it usually lasts longer.  However, since implementing these changes we've seen a few things that can cause the prompt to show up more frequently.  Google has an "official" answer here with some recommended steps to avoid the repeated prompts.  But in general, we've been seeing this when staff access their @dcgschools account from multiple devices (school laptop, personal phone, etc.) or when they switch between multiple accounts on the same computer.  Google seems to read this as potentially suspicious activity, and as a security precaution, it prompts for the additional verification step.  One of our staff was getting the 2-step verification every time they logged into Chrome, and after investigating, we learned she was switching back and forth between her school and work emails daily.  We think this person was using the same password for both accounts, which also put Google on high alert.  Once we removed her personal accounts from Chrome, the repeated prompts stopped.