One idea would be a simple "Person" class that would have ivars "firstName" and "lastName" (and others per coder's choice).
The object structure (ivars) would be the two names plus any more.
A "calculation method" you could code a method called "getFullName" that would return the first and last names joined (separated by a space).
A "logic method" could be "hasLongName" that would return true if the full name length is over some
defined length (decided by you). To get the length of a string, use
If you are feeling more ambitious, you could code up a temperature calculator that would take one temperature in a "base" unit (e.g. say Fahrenheit or other), and then compute other temperatures from that base (one other or as many as you like -- wiki conversions).