The result of the calculation is "not a number", but not always. What is the problem?

Question

C++ / C#

Hello. There is a program that calculates a value and sets it to a TextBox. Sometimes a number is written there, and sometimes it writes "not a number" in the text. What could be the problem?

Answer 1

Division by zero, for example.
In the debugger, look at what numbers are written there and everything will become clear.