Changing Posative numbers to negative

[Penny]

Hi

I was wondering if it was possible to change a positive
number in Ecel to a negative number (in bulk so not by
putting a - sign in front of the number). I have 3000
cells that need to be made a negative number that are
posative.

Regards

 

[Jordon]

I was wondering if it was possible to change a positive
number in Ecel to a negative number (in bulk so not by
putting a - sign in front of the number). I have 3000
cells that need to be made a negative number that are
posative.

=a1-(a1*2)

Jordon