Is it possible to add an array as double?

Basically im having problems programming an array as double.

I have it as ' public arrytotal() as double ', however i keep getting the error messages

1.? Error?5?Operator '+' is not defined for types '2-dimensional array of Double' and '2-dimensional array of Double'.?C:\Users\Alex\Documents\Cafe Assignment\Cafe Assignmentconverthome\Backup\WindowsApplication2\Form2.vb?115?22?WindowsApplication2
?

and

2.? Error?1?Value of type 'Double' cannot be converted to '2-dimensional array of Double'.?C:\Users\Alex\Documents\Cafe Assignment\Cafe Assignmentconverthome\Backup\WindowsApplication2\Form2.vb?84?19?WindowsApplication2

is it possible to program an dynamic array as a double? i have seen examples of this online, but cannot seem to do it.

any help would be great,

cheers!