Rename the cube, pCube1, as LeftHand.
To convert the polygonal cube to a subdivision surface, select
Modify > Convert > Polygons to
Press 3 on your keyboard (to select Display > Subdiv Surface
Smoothness > Fine).
Also press 5 (to select Shading > Smooth Shade All).
With the Smoothness set to Fine, you can see that the conversion to a
subdivision surface creates a rounded, smooth shape. By pressing 3, the
subdivision surface is displayed more precisely in the scene view. This
gives a closer approximation of what the surface will look like when you
create a rendered image of the scene.
As an alternative, you could have chosen a rough smoothness (press 1) so
that Maya processes your editing changes in the scene view more quickly.
Regardless of the smoothness in the scene view, surfaces always are
displayed precisely in rendered images of the scene.