typing test

The typing test which we're doing in computer class, is very boring and frustrating at the same time. The only thing that im good in, is in Accuracy, in all of the rest, i suck. In the first 2 tries i really sucked, but on the third and last one, i went up 2 wpm on Gross Speed. I hate this test because it frustrates me when i get an error, because i cant go back and redo it. I really want to improve before chritmas holiday. My goal is to get 98% in Accuracy, 19wpm in Gross Speed, and 16 in Net Speed.
From what i understaned from internet is that Gross speed tells the total number of characters you have typed divided by your time. Net speed is your total speed with errors calculated into the result.