Deleting +4 of a Zip Code in a Column

I have a column that contains thousands of Zip Codes. Some of them are just the five digit zip code, example, 20740. This is great and what I need the entire column to be. What is no good, is that many zip codes contain the +4 number, example, 20740-4321.

Example of the Column:

20740
20781
20781-2345
20033
20103-4224

Is there a way to get rid of all '-####' in the column, to allow the entire column to contain ##### for zip code?

Hi and welcome to the board
Select your range - data - text to columns - check fixed width- set the break line so that is before the dash
OK
delete the 2nd column