Calculating for personal car mileage?

I want to create a formula that will calculate the amount of dollar due
employee if he uses his personal car for business purposes. I cannot figure
out how to avoid to overwrite the formula I created to perform that function.
For example, my formula is "=A1*0.485", but the formula is over written every
time I enter 10 (miles) in A1. How do I solve this problem? Please help!!!

Elau wrote:
> I want to create a formula that will calculate the amount of dollar due
> employee if he uses his personal car for business purposes. I cannot figure
> out how to avoid to overwrite the formula I created to perform that function.
> For example, my formula is "=A1*0.485", but the formula is over written every
> time I enter 10 (miles) in A1. How do I solve this problem? Please help!!!

In A1 put your miles. Put the formula in A2.

gls858