Problem with WD Advanced Format drive in LINUX (WD15EARS)

BTW Here’s what I’m planning to do, can someone tell me if this will work:

mkpart primary ext2 40 3750000

I’m assuming this will create a partition from secot 40 to sector 3,750,000, which according to my calculations should be approx. 15GB

I would then create another partition like so

mkpart primary ext2 3750008 7,500,008

which hopefully creates another 15GB partition

Followed by

mkpart primary ext2 7500016 -1

which should create one more partition, taking up the rest of the space on the drive

Or am I going about this the wrong way ?