This examples shows how to add partition on top of existing partitions

parted) unit s 
(parted) mkpart primary 524285952 534520703  

# Create a new primary partition
# In this example, the new partition will start at sector 524285952 and 
# end at sector 534520703, which should give you a partition size of 
# around 5GB (assuming 512-byte sectors).
(parted) set 2 boot on
Marking a partition as bootable does not necessarily make it the active boot partition. 
The grub needs to point to this partition for booting.

End sector = Start sector + ((Desired partition size in bytes) / (Sector size in bytes))

Here desired partition size is 5 GB

End sector = 524285952 + ((5 * 1024 * 1024 * 1024) / 512) End sector = 534520703