Exclude URLs

Hello. I am trying to exclude about 300 pages that have dynamic data from being cached that are all named:

https://mysite.com/sample/page1/
https://mysite.com/sample/page2/
https://mysite.com/sample/page3/
https://mysite.com/sample/page4/
https://mysite.com/sample/page300/

I have tried using:
Settings>Exclude URLs> /sample
however, the pages still show up in the dashboard as cached. Not sure what I am doing wrong. Does there need to be a trailing slash /sample/ or /sample/*

Thanks