It's basically returning the boxes_needed. 1 box can contain 10 items. So if the items typed by the user is 102 then the code should return 11 boxes.
Is there a way to divide that rounds upwards if there is a non-zero remainder?
For your use case, use integer arithmetic. There is a simple technique for converting integer floor division into ceiling division:
items = 102
boxsize = 10
num_boxes = (items + boxsize - 1) // boxsize
Alternatively, use negation to convert floor division to ceiling division:
num_boxes = -(items // -boxsize)