Check digit

Hey kiddo, do you know how we write and read numbers? Yes, we use digits like 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. But sometimes, we make mistakes while writing them, and we don't even know it! To prevent these mistakes, we use something called a check digit.

A check digit is like a little helper number that helps us check if the main number we wrote is correct or not. It's like a small secret code that only some smart people know how to find out.

Now let me show you how it works by using an example:

Say you want to buy some candies from a shop, and they cost $10. You have $5 in your piggy bank, and you borrow $5 from your mom to complete the purchase. So, you have the amount $10 in total.

But wait, what if you count the money again, and you mistakenly count it as $9 or $11? You wouldn't realize your mistake until the shopkeeper tells you the correct amount. So, to avoid such confusion, you can add a check digit to your money count.

To create a check digit for your money count, you can add up all the digits in your total amount. In this case, it is 1+0 = 1. So, your check digit will be 1. Now, whenever you count money, you add up all the digits, decide on the check digit, and keep in mind that it should always add up to your check digit.

In this way, you won't have to worry about making mistakes in counting money. Similarly, check digits are used in many other things like credit card numbers, social security numbers, bar codes, and many more to make sure no errors occur in the data. I hope this makes sense to you, kiddo!