you might like the nudge keys for this… go:
Rhinoceros > Preferences > Modeling Aids > Nudge
set the Nudge keys to ‘arrow keys’ (should be like this by default i believe)
for Nudge Steps, enter .125 in the ‘nudge key alone’ field
select the object and push the left arrow key… if you tap the key, it will move one increment… press and hold moves it further faster… there’s a cumulative counter to keep track of your amounts…
another way is with the gumball… with gumball engaged select the object then click the red arrow… type -1/4 or -.25 to move left a quarter unit.
one other thing regarding 0,0,0 in rhino.
0 is a shortcut for 0,0,0… as in, just type a single zero for origin.
note* there is currently a bug in the nudge preference which only allows 3 decimal place to be used for the increments…
1/8" increments are ok since it’s 0.125… you can’t do 1/16" though since that’s 0.0625
discourse.mcneel.com/t/wish-more-decimal-places-in-nudge-preferences/15600