Newbie: Sum and Average of decimal numbers

Hallo experts,
As a first post in this forum I would like to know some knowledge about basic Excel-2010 functions.
I have given a table with some decimal values like e.g 0.3658 0.358 0.485 0.7863 0.558 0.858 0.985, I want to find the sum and average of these number.

1) I have tried the autosum or auto Function =AVERAGE(A2:A7) but it yields #DIV/0! error
2) when I use =AVERAGEA(A2:A7), it yield ans=0
3) puttin =ROUND(AVERAGEA(H2:H23);3) also yields 0;

any other suggestion are welcome..

Best Regards
Ali

Thanks alot guys.
I rechked my excel, The windows and every thing is German, but a English language package has been installed. the changing of . to , worked