We know that there are a total of 1000 milliliters in a 1 liter. So we first need to multiply 1000milliliters by 5 in order to calculate how much is in 5 liters which is what the coach is asking for...
1000 * 5 = 5000 milliliters
Since each water bottle only holds 500 milliliters we need to divide this amount by the total that the coach needs in milliliters.
5000 / 500 = 10
Finally, we can see that Audrey needs to buy a total of 10 water bottles to have exactly enough water.
