Question: I have two columns A and B in a google spreadsheet.

I want to find all the numbers that are in column A but not in B. How do I do that?

B could have the same numbers from column A. 

So if column A has numbers: 1, 2, 3
and B has numbers 3, 4,5

I want to get all the numbers that are in A but not in B:
1, 2

How do I do that using google spread sheet?

Answer: 
Based on Kate aswer I have been able to negate not only one column, but several. 

Kate solution was as follows:

> 
> =FILTER(A:A, ISNA(MATCH(A:A, B:B, 0)))
> 
> 
> 

Where "B:B" is defining that what is going to be returned is A:A less B:B. 

But if you want to return A:A, lees B:B, less C:C, less D:D, etc? 
Just insert B:B, C:C and D:D inside {}, then:

```
=FILTER(A:A; ISNA(MATCH(A:A; {B:B;C:C;D:D}; 0)))

```

I hope this may help others like me. I was seeking for a solution that would not bring what's present in some set of columns. 

Thanks!
In column C, use vlookup from A against B. For example

```
C1 = vlookup(A1,B:B,1)
C2 = vlookup(A2,B:B,1)
...

```

If B does not contain A, then it shows `#N/A`