Hi Hood, Thanks for the reply.
I've noticed that adding a negative value only works for fields that have %+.4f in the format string, is it possible to use it on a DRO that has %.4f as a format string (no positive value).
I only ask because it's a DRO I use for material size, so in the DRO it has 20.0000 not +20.0000.
So it seems that unless I have the + I cannot use the negative calculation, is there a way around this?
Darc