There are 2 cups in a pint. Therefore, to convert 0.5 cups to pints, we need to divide by 2:
0.5 cups ÷ 2 = 0.25 pints
Ms. Dean needs 0.25 pints of milk for each of her 28 students:
0.25 pints/student × 28 students = 7 pints
Therefore, Ms. Dean needs 7 pints of milk for her class.