Aprincipal wants to order enough notebooks for 624 students. the note books come in boxes of 28. how many boxes should he order?

Try this:

624 students

= 22.3 boxes.

28 students/box

Boxes are sold unopened, so the correct answer here is 23 boxes.

23 boxes times 28 notebooks per box comes to 644 notebooks.  This is enough to put a notebook in the hands of every one of the 624 students and have 20 notebooks left over.

goog may have it for you