Answer: each of the students took 1/4 of an eraser home.
Explanation:
On the last period our teacher had 1/2 of an eraser left. She gave it equally to 2 students. This means that the amount of eraser that each student takes home would be
(1/2)/2 = 1/2 × 1/2 = 1/4 of an eraser. Converting to decimal, it becomes 0.25 of an eraser.