Thread and scientific notation

How does the main thread know that other threads have been completed?
Event is triggered when the sub-thread ends.
The main thread waits for the event to be triggered. When the event is triggered, it indicates that the sub-thread has finished running.

Add:
Use manualresetevent or autoresetevent in combination with the waithandle. waitone or waithandle. waitall method. For details, refer to the msdn Library

Add scientific notation
Allmoney + =
Convert. todecimal (decimal. parse ("1.38e9 ",
System. Globalization. numberstyles. Float ));