10 glasses per box
Let's just write it out:
Box #1 = 10 glasses
Box #2 = 10 glasses
Box #3 = 10 glasses
Box #4 = 6 glasses (not full!)
Total: 36 glasses
You need 4 boxes.
Another way is 36 glasses divided by 10 glasses per box = 3.6 boxes. You can't have 0.6 boxes; you can only work with WHOLE numbers. So it would be 4 boxes.
