New butter please

Our Irish friends do their shopping at Costco, as a result everything they have is in bulk.

The butter nearly takes up their whole fridge. They have a sheet on the wall with bets on when the butter will run out. Never one to miss out on a bet, I threw $5 into the equation. 

Using a powerful scientific calculation (measuring how much has already been used and how much is left with the use of my thumb) I reckon another trip to Costco will be needed on November 2nd.