What are irrational numbers? How do they differ from rational numbers? Give examples.

Classify the following number as rational and irrational. Give reasons to support your answer.

$\sqrt{\frac{3}{81}}$

Classify the following numbers as rational and irrational. Give reasons to support your answer.

$\sqrt{361}$

Classify the following numbers as rational or irrational. Give reasons to support your answer.

$\sqrt{21}$

Classify the following numbers as rational and irrational. Give reasons to support your answer.

$\sqrt{1.44}$

Classify the following number as rational or irrational. Give reason to support your answer.

$\frac{2}{3}\sqrt{6}$

Classify the following number as rational and irrational. Give reasons to support your answer.

$4.1276$

Classify the following number as rational or irrational. Give reasons to support your answer.

$\frac{22}{7}$

Classify the following number as rational or irrational. Give reason to support your answer.

$1.232332333\dots$