Every days a school day, had to Google jetons. Very interestingThe zero symbol plays a vital part in our modern ( not really that modern ) number system.
Consider the number three hundred and six when you don't have a zero symbol. How do you write it? You could write 3 6 or 36 or 3 , 6 but that would be confusing. With 306 it makes it clear what you mean. It forces digits to have a place value and enables calculation by writing numbers in columns.
Without zero, we would be using a system like the Romans, 306 = CCCVI. Try doing long addition/subtraction using just the Roman system. You will soon see why mediaeval people used counting tables and jetons.