One way just assuming since you done't say what should happen if C is less
than 10 or greater than 19

=IF(AND(C1<10,C119),"none",IF(C1=19,1,C1-9))

Regards,

Peo Sjoblom

"Tomas" wrote:

How would I do the following:
A+B = C,
if C = 10 then D = 1
if C = 11 then D = 2
C = 12 then D = 3
and so on
C = 19 then D = 1
thank you!
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