mirror modifier

Support Basics & Interface
1

Hi all
I am very new to blender.
Im using the default cube.
I go into front ortho view. I move the cube left and align the right edge with the z axis. Go into edit mode , face select the face near the z axis, delete the face. When i go to apply the mirror modifier it does not mirror the cube , only adds the face back that i just deleted.

Can anyone help with any suggestion on what i am doing wrong???
Many Thanks in advanced

2

It is mirroring the cube but not along the grid origin. Unless told otherwise it mirror across the objects origin. When you moved the bube in object mode you were also moving the origin so what you get is a cube mirrored on itself. Instead of moving the cube in object mode move it in edit mode. This will keep the origin in its original location.