Try this:
=PRODUCT(A1:C1)/SUM(PRODUCT(A1:C1),PRODUCT(D1:F1),PRODUCT(G1:I1))

PRODUCT and SUM both ignore text inputs.

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Best Regards,

Luke M
"Zuo" wrote in message
...
I have a simple formula (A1*B1*C1)/((A1*B1*C1)+(D1*E1*F1)+(G1*H1*I1)).
However there are times when the values of D through F or the G through I
denominators can change into letters (if D changes to a letter so do E
and
F, same happens to H and I if G changes to a letter). I need the formula
to
complete the calculation by assuming any value that becomes a letter as
zero.


Thanks for your help.

Regards,

ZUO