Leading digit

Have you ever seen a really big number like 10,000,000,000? Well, the first number you see in that big number is called the leading digit. It's like the captain of the team or the leader of the group. The leading digit helps us understand the size of the number without having to count each and every digit.

Let's say we have two big numbers, 100,000 and 500,000. Both numbers have five digits, but the leading digits are different. In 100,000 the leading digit is 1, and in 500,000 the leading digit is 5. So even though they have the same number of digits, we know that 500,000 is a bigger number because its leading digit is bigger.

So next time you see a really big number, remember to check out its leading digit to help you understand just how big it really is.