Try adding a .5 to your rounded numbers so the center of the part goes to the mouse rather than the edge, so…
( math.floor( divided[number] + .5 ) * 4
( math.ceil( divided[number] - .5 ) * 4
Try adding a .5 to your rounded numbers so the center of the part goes to the mouse rather than the edge, so…
( math.floor( divided[number] + .5 ) * 4
( math.ceil( divided[number] - .5 ) * 4