How to delete schema object?

I had created a section named "Calculator" in General Workplace. Now when I'm trying to delete the schema object for the above created section, I am getting an error message stating, "Unable to delete item 'UsrCalculator' of package 'Custom'. It has dependent items." 

Sharing the screenshot of the error.

Please help me out in resolving the issue to delete the schema object.

Thanks in advance!!