Your question is Spreadsheet Class Design. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Describe how you would design a simple spreadsheet application such as Excel where cells can contain numerical values, mathematical expressions, and references to other cells; draw a class diagram and explain how you would represent and handle the data, including how you would avoid loops in referenced cells.