The boys each eat about 3 ounces of breastmilk a feeding
x2 boys
= 6 ounces a feeding
x 9 feedings a day
= 54 ounces a day
x 7 days a week
= 378 ounces a week
/ 128 (number of ounces in a gallon)
= 2.95 gallons of milk a week
~12 gallons a month
~ 159 gallons a year