Are all non-irrational numbers rational?
87410
Are there real numbers that are neither rational nor irrational?
24706
Is there a rational number between any two irrationals?
98666
Continuity defined for rational and irrational numbers
22800
Can $\sqrt{n} + \sqrt{m}$ be rational if neither $n,m$ are perfect squares?
147363
Is $\large \frac {\pi}{e}$ rational, irrational, or trandescendal?
122226
Incorrect logic in popular proof of the irrationality of $\sqrt2$?
34825
Intuitive explanation for how could there be "more" irrational numbers than rational?
138162
Do Irrationals form a group?
23164
Why are irrational numbers uncountable and rationals countable?
109175
Why is it hard to prove whether $\pi+e$ is an irrational number?
129139
Is every discrete absolute value non-archimedean?
20619
Finding Rational numbers
29780
If $x$ is a positive rational but not an integer, is $x^x$ irrational?
28230
What bizarrities lurk within the decimal expansion of an irrational number?
147534
The set of irrational numbers is not a $F_{\sigma}$ set.
158730
Is $\ln(\ln(n))$ irrational for any integer $n>1$?
13592
How can $\pi$ be irrational if it can be calculated using an infinite series of rational numbers?