The very first thing you should do is to give them some idea of what the article is all about. A sentence or two describing the content, and who it is targeted to, is essential. If you don't do this, they might read a paragraph or two and make a decision based on that. You might have a great article that is rejected, simply because the first few sentences don't get their attention. This is absolutely necessary.
Publishers have different amounts of space available for an article every time they publish.
If they have to take the time to figure out how long it is, it might just end up in their trash. Of course not, but it does give you a shot at having it read. There is absolutely nothing that will get your article rejected faster. Think about it - if you submit an article with these types of errors, a question is immediately raised as to the accuracy of the content. The best thing is to have someone else proof it for you prior to submission.