Finding Value which isn't in a table

I need to find a value which isn't given in the table. The table is from 1 to 10, but the number 9 isn't show. I need to show the number 9 isn't show. How do I do this?

the table name is Table1, and the column name is numbers.

I would use a comparison to return TRUE or FALSE about which numbers are in the data frame column and then use those TRUE/FALSE values to make a subset of the candidate numbers.

DF <- data.frame(numbers=c(5,6,3,4,7,1,2,8,10,5,2,7,1,8,10,3,2))                 
TrueFalse <- !c(1:10) %in% DF$numbers #Returns TRUE if a number is missing.
c(1:10)[TrueFalse] #Returns 9