I'm currently using a string as single value

say:

"
Dim test As String
test = 0
"


and with a command button:

"
test = test + 0.1
"


it seems to work fine on my computer and on some others
when i used single, sometimes it turned the value test to 0.5000001

but if i declare test as a string it all works out fine
can anyone explain to me how this is possible ?