Interesting question, thanks, Tom

While method 2 appears incomplete, it is not difficult to deduce what it should be: given that all other methods refer to sysdatetime(), which is returned as a datetime2 data type, we can presume the actual method should have been declare @t datetime2 = sysdatetime()

select cast(cast(reverse(substring(cast(@t as binary(9)),2,5))

as binary(5)) as bigint)*100