Question

Bianca poured four cups of milk from a full half-gallon container. How many cups of milk were left in the container?

Answer 1

Given: 
4 cups of milk form a full half gallon container.

1 liquid gallon contains 16 cups.

1/2 gallon * 16 cups/gal = 16 cups / 2 = 8 cups

8 cups - 4 cups = 4 cups left.

There are 4 cups of milk left in the half-gallon container.