Press [Original Settng].
Press [Original Size].
Specify the original size, and then press [OK].
Select original orientation.
Press [OK].
Press [Dup./Combine/Series].
Press [Series/Poster].
Press [Poster].
Select the number of sheets of paper you want to put in one poster.
Press [OK] twice.
Select the paper tray.
Place the originals, and then press [Start].