Fractional Plates vs 5 lbs Jumps

[JohnTurner]

Currently I can deadlift 280 lbs for 5 reps.
My goal is to do 300 lbs for 5 reps by the end of this year.
That's 5 lbs per quarter which I believe is realistic for my 70 year old body which takes longer to recover and adapt.
Should I use fractional plates to add up to 5 lbs by the end of each quarter or simply add 5 lbs at the end of each quarter?

Thanks in advance for your responses!

- John

[Mark Rippetoe]

Next time you train, go to 285 and see what happens. You should probably be doing sets of 3 instead of 5.

[SouthernLifter]

How much do you weight and how tall are you? That could put the thing into perspective.