Round the number 3,245.6789 to the nearest thousandth.

To round the number 3,245.6789 to the nearest thousandth, you look at the digit in the fourth decimal place, which is 9. Since 9 is greater than 5, you round the third decimal place (8) up by one. This gives you 3,245.679. Now, here's a fun fact: rounding is not just for math class; it's also key in fields like finance for reporting figures and in programming for data handling. Accurate rounding ensures that data is not only precise but also easily understood. Also, when rounding, people often make the mistake of not looking at the next digit properly! Remember, if you’re rounding up and the digit that you're looking at is less than 5, you simply keep the digit as is. Happy rounding!