How many ml must be added to four and 1 quarter to make 5 liters?

To solve this problem, we first need to convert 4 and 1/4 to a decimal, which is 4.25 liters. Next, we subtract 4.25 liters from 5 liters to find out how many milliliters must be added. This calculation gives us 750 milliliters. Therefore, 750 milliliters must be added to 4 and 1/4 liters to make 5 liters.