How do I make this formula work =if(a1=(b10:b20),"good","bad").

[AK]

I need to check if the number in cell a1 equals one of the numbers in cells
b10 though b20.

 

[tjtjjtjt]

AK,

This should do it:
=IF(COUNTIF(B1:B10,A1)>0,"good","bad")

tj

 

[Andy Brown]

I need to check if the number in cell a1 equals one of the numbers in
cells

b10 though b20.

=IF(ISERROR(MATCH(A1,$B$10:$B$20,0)),"Bad","Good")

Rgds,
Andy