####### Showing up in the desired cell after completing an expression

Hi everyone,
I am a very inexperienced and pathetic excel user. Im sure it is something simple but i cant work it out. I needed to sum up a column of values and this is what i got
$1,830.00
$91.80
$328.90
$945.50
$112.20
$378.00
#######

The expression i had used to total this is =SUM(G5:G10)

Any advice would be really handy as the assignment is due in four days on the 8th of June

Thanks Mike