Assuming she needs 4 tablespoons of water for every 2 of oil, the ration table would start with x as your water and y as your oil. 0/0, then adding 1 tablespoon of water would mean she needs 1/2 tablespoon of oil, giving your ration a 0.5:1 ratio. adding one tablespoon of water will add 0.5 tablespoons of oil.
