To add to what Richard has - rightly - said ...
Try it in C# using different numeric types: Double, Float, and Decimal:
Console.WriteLine(128.23 - (118.23 + 10));
Console.WriteLine(128.23f - (118.23f + 10f));
Console.WriteLine(128.23m - (118.23m + 10m));
The results probably aren't what you expected:
That's why .NET has a Decimal numeric type.