How did I use so many operations? [Google Calendar]

I have 7 separate calendars that I need to copy into one in an ongoing manner.
I have one scenario for each calendar that looks like this:

Each scenario works fine.
I’m trying to understand how my scenarios are using nearly 100 operations a day, each.
I ran through 10,000 operations in half a month.

How can I modify my scenarios to use less operations?

Was the frequency too high? I have already changed frequency from every 15 minutes to once a day.

Yes, I can see that your scenario is scheduled to run every 15 minutes hence it consumes 1 operation for every run to check if there are new updates available to execute the scenario.

This way every day the scenario is spending almost 96 operations (just to check if new items are there to process).

You can see the check run operations spend by visiting the history tab and turning on the Show check run button (in the top right corner).

To reduce the operations consumption, I would recommend you to please increase the scenario run time interval to 30 or 60 minutes.