Ceremonial Counterspell +100% energy = +4 skill : when to round

[Plane]

M12's rules seem to allow that if you do a ceremonial version (5 seconds x 10 = 50 seconds to cast) of Counterspell (M121) that if you doubled the energy input you get +4 to skill, making it more likely you will win the contest.

How would this work against a spell which cost 1 energy though?

Normally I would assume you would need to round up 0.5 to 1.

In this case though, when casting ceremonially should that count as spending x2 energy to get +4?

Or would you first round 0.5 up to 1, and then need to double that to 2 energy to get the +4 bonus?