So, Sam filled 6 glasses with 2/3 liters. We want to find out how many liters of juice he used.
To find this out we do 6 * 2/3.
(2/3+2/3+2/3+2/3+2/3+2/3)
(12/3) (Denominator stays the same)
12/3 = 4
Sam uses 4 liters.
Hope this helps you! (:
-Hamilton1757