in ubuntu there is many method by which you can format your pendrive
1 - by Disk utility see the video // simplest way
2- by Gparted tool see the video
// you can install it from Ubuntu software center
or
you can install is by typing
sudo apt-get install gparted
3- by using Terminal see the video
go to super mode by typing "su" followed by super mode password
fdisk -l
that will show all the volume in your pc or you can also use the
df
to see the usb flash drive suppose it may be /deb/sdb1
umount /dev/sdb1
that un mount the drive
mkfs.vfat /dev/sdb1
to format drive into fat32 format