1)
From the information given,
Quantity of icecream to be shared = 1/2 gallon
We want to divide 1/2 gallon into 1 cup servings
A cup is one sixteenth of a gallon. This means that
1 cup = 1/16 gallon
The model is shown below
The length of the rectangle represents 1 gallon. It is divided into 16 cups. A we count the number of cups from left to right, we would find out that when we count the 8th cup, we would have reach one half of the gallon.
Let x represent the number of 1 cup servings that we would get. Thus, we have the following equations
1 cup = 1/16 gallon
x cups = 1/2 gallon
By cross multiplying,
1 * 1/2 = x * 1/16
1/2 = x/16
By cross multiplying again,
x = 1/2 * 16
x = 8
8 serving dishes would be needed