Write whether the given number is rational or irrational number.

$\sqrt{2}\times \sqrt{8}$

Write whether the given number is rational or irrational number.

$-\sqrt{2}\times \sqrt{8}$

Write whether the given number is rational or irrational number.

$\left(4-\sqrt{2}\right)\times \left(2+\frac{1}{\sqrt{2}}\right)$

Write whether the given number is rational or irrational number.

$9990$

Write whether the given number is rational or irrational number.

${14}^{-28}$

Find the greatest and the least of the following rational numbers: 

$-12,8,-3,12,-8,3,0$

Find the greatest and the least of the following rational numbers: 

$\frac{2}{3},\frac{3}{5},\frac{2}{5},\frac{3}{4},\frac{3}{8}$

Represent the following number on number line.

$\frac{-7}{4}$

Represent the following number on number line.

$0$