Venn Diagram - Number System:

The expression is .

                    (Square root: )

Observe that the decimal () of the number is repeating.

The number is a rational number.

Obeserve the vendiagram:

\
• The number is not a Natural number (N),
\

           not a Whole number (W), and not an   Integer (Z).

\
• The number is a rational number (Q).         
\
• All rational numbers (Q) are real numbers (R).
\

The number belongs to Q and R.