Math Is Fun Forum

Here is the entire sequence that I was given :
4.21.30.28.20.30.17.36.35.21.54.1.6.10.11.13.15.6.18.24.10.54.31.37.6.30.25.26.26.10.28.41.40.54.13.44.2.13.38.11.54.19.40.42
I don't even know where to begin, I'm not used to that kind of puzzles, I only do letters puzzled...
Do I need to put them in order? To find an algorithm which could fit?
Please help !
Thanks
Amber