GUI Calculator

I'm new to programming and joined a class at a local college, I'm only looking to see how to work this out. I am completly new to programming, and the teacher threw this assignment at us pretty fast and I feel I dont understand it enough to even know how to work it out.

Provide a graphical user interface for a calculator using Dr. Stroustrup’s code in the textbook as the base

1. Consider the following menu buttons (free design):
• decimal digits (0, . . . ,9) and decimal dot (.)
• parentheses (left ( and right ) )
• change sign (±) to change sign from + to − and from − to +in the displayed number
• four arithmetic operators (+,−,,/)
• percentage of a number (%) which is equivalent to dividing the number by 100
• square root (p or SQRT)
• exponentiation (ˆ) which takes a number to a power (example: 2.1ˆ3.2). Note that bpq = b(pq).
• result (=) to display a result
• clear (CR) to clear the display
• exit/quit (OFF) to exit from the program

2. All computations should be done using type double. Every number is treated as a floating-point decimal number
(even if it was entered without a floating-point dot).

3. If an operation cannot be handled, display the word “Error” (as in the division by 0, or calculating p−1)

4. The display should be implemented as an out_box.

5. You should not use any in_boxes. To enter numbers you use digit buttons, possibly with a decimal dot.
Here's a calculator that I have done that might help you with some calcualtions you want to do, but I don't have a GUI. (Sorry if its a bit long)
FYI I'm still a beginner but I thought this might help you