real number. Article #23. Vol 9, pg 973.
The set of real numbers is probably best described as the set of numbers that includes all numbers that most of us will ever care about. Put another way, the real numbers are: all of the numbers present on an infinitely long number line.
One final description of real numbers, to help you identify them in the wild: a real number can always be written out as a series of digits, though the number of digits after the decimal point might be infinite.
The set of real numbers includes the following subsets of numbers:
– Positive and negative integers
– Rational numbers (can be expressed as a fraction)
– Irrational numbers (can’t be expressed as a fraction)
“real number.” Encyclopedia Britannica. 15th ed. 2010. Vol 9, pg 973.