=A1*0.9^3

HTH. Best wishes Harald

"Fran" skrev i melding
...
For example, take a number 100 (A1). In the formula in B1 - take A1 and
multiply it by 10% - TAKE THE RESULT of that and Multiply it by 10% and
take
the RESULT of thank and multiply by 10%. Answer should be 72.9 Take 10%
of
100 would be 90, 10% of 90 would be 81, 10% of 81 would be 72.9. How do I
write that formula in ONE LINE??????