Name: Rational and irrational numbers: solution walkthrough
Uploaded: 2026-11-13
Duration: 1 min 24 s
Description: Which of the following numbers is irrational? Try it, then watch the animated solution.

A rational number can be written as a fraction of two integers. An irrational number cannot.

0.\overline{3}

goes on forever, but it repeats, and it equals

\tfrac13

. And

\tfrac{22}{7}

is already a fraction.

\sqrt{\tfrac{9}{16}} = \tfrac34

, because

9

and

16

are both perfect squares. Rational.

12

sits between the perfect squares

9

and

16

, so

\sqrt{12}

is between

3

and

4

: not a whole number.

The square root of a whole number that is not a perfect square is irrational:

\sqrt{12} = 3.4641\ldots

Try it first