You can put this solution on YOUR website! You have 315 students.
There are 21 students per class.
How many classes are there?
Answer should be 15 classes because 15 * 21 = 315.
You make up a story where the punchline is the number 15. E.g.
It takes one full can of dweezil oil to lubricate a fernblatz machine for one full 8-hour shift at the dooflagger factory. If the stock of dweezil oil in the storeroom is 315 cans, how many fernblatz machines can the plant manager continue to have in operation if he wants to continue 3-shift per day operations and a new shipment of dweezil oil is not due for 7 days?
John
My calculator said it, I believe it, that settles it