White Leghorn large fowl are serious layers (good choice of hen) and will be consuming 150 grammes of pellet feed a day, if that was all they ate. 1 level scoop of Flubenvet treats 2 Kg of feed which will be enough for both of them for the 7 days. So mix scoop with Olive Oil and (stiring thoroughly every time) give them each a proportion of the mix. Having done this before I can say that if you mix 1.5mL of oil with the scoop the resulting thin paste is about 3.3mL. So give them each 0.2 mL a day. There is some left over, but it is difficult to draw up and there is a margin for error anyway.