A real number is a number corresponding to a point on the real number line.
The field of all rational and irrational numbers is called the real numbers, or simply the "reals, " and denoted R. The set of real numbers is also called the continuum, denoted c. The set of reals is called Reals in the Wolfram Language, and a number x can be tested to see if it is a member of the reals using the command Element[x, Reals], and expressions that are real numbers have the Head of Real.
middle school level (California grade 7 standard)