I've took a model from web (Plottergram from tinkercad.com) and wanted to modify it namely enlarge the table in one dimension. I did't need it to have rounded corners so it's enough to add a cube that fits table's width and height. In this very case I could do this in TinkerCAD itselft, but for some reason I was working offline, so I've got just .stl and Blender.
Now, to fit the width and height I just manually "carefully changed" dimensions of the created cube and then rounded the decimal number assuming the model has some reasonable dimensions. But I wonder if I can do this (resizing/moving) so that a plane of the box fits the corresponding plane of the existent detail in a simple way. Some editors use so-called "work plane" which can be attached to a plane of an object and then resizing/moving may behave in a "sticky" way in regard to it (such thing is in TinkerCAD, too); but it seems that there's no such tool in Blender (at least that is named work plane; this is according to a thread in some non-english forum). So, is there some convenient tool to do this?
PS the following image is added to comment the first answer: