if I have a message that I want to get to later, like much later, and I leave it for perhaps five or seven or 10 days before I read it because I don't want to forget it's there so I leave the notification, and then I go to read it, it will not clear the number badge next to it. it will still show us one new text even though I have read the text many times. the only way to get rid of the badge number is to delete the text, or in some cases delete the entire thread