Dim Num 1 and Num2 are single precision, which means that Num 1 and num 2 are defined as single precision integers.

Dim strnum 1, strnum 2asstring means strnum 1 and strnum 2 are defined as strings.

Dim FirstNum As Boolean means that FirstNum is defined as Boolean.

You can pull it out by reading it in the help file, and there are many on the internet.