Completeness of the real numbers

The real numbers are all the numbers that we can think of. They include regular numbers like 4, 5, and -7, but they also include numbers that are in between these existing numbers. For example, the number 4.5 is in between 4 and 5, so it's also considered to be a real number. All the numbers that we can think of, no matter how small or big, are considered to be real numbers. That means that all possible numbers are real numbers, so they are complete.