Order of operations can sometimes cause calculations to resolve in ways we did not mean for. Using parenthesis can nudge the program more in the direction you mean for it to calculate an answer instead of the ordinary precedence set by the language. This is a C# program, and you can read about C# precedence here: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/arithmetic-operators

Why are there "()" here?