Hello Joseph,
This happens when you import directly project with "Import project(s) from file system" with "Archive" method.
Problem is that the project is designed with relative path inclusion and linked folder resources; if copied into your workspace directly from archived, this mess with project architecture and makefile configuration.
What you want to do is: first, extract the zip archived into your hard drive, in a folder close to C:\ or better in your workspace, then import from the filesystem and choose "Root directory" method, and search for your folder.

Untick "Copy projects into workspace option
Note: Initially there were two projects to import from the zip archived provided by Atmosphere IDE :
- RapidIot_Base (low-level drivers, to be builded first)
- Application project, in your case: "Embedded Mathematical Operation Demo"
Recently an update has been made to ease user experience and RapidIot_Base is directly included in the application project. So only one project has to be imported. Don't know if it's the case for your project.
Regards,
Theophile