Give an example of a real number that is irrational

√2 is a real number that is irrational.

Pi, which begins with 3.14, is one of the most common irrational numbers. Pi is determined by calculating the ratio of the circumference of a circle (the distance around the circle) to the diameter of that same circle (the distance across the circle). Pi has been calculated to over a quadrillion decimal places, but no pattern has ever been found; therefore it is an irrational number. The Square Root of 2, written as √2, is also an irrational number. The first part of this number would be written as 1.41421356237 ... but the numbers go on into infinity and do not ever repeat, and they do not ever terminate. A square root is the opposite of squaring a number, meaning that the square root of two times the square root of two equals two. This means that 1.41421356237 ... multiplied by 1.41421356237 ... equals two, but it is difficult to be exact in showing this because the square root of two does not end, so when you actually do the multiplication, the resulting number will be close to two, but will not actually be two exactly. Because the square root of two never repeats and never ends, it is an irrational number. Many other square roots and cubed roots are irrational numbers; however, not all square roots are.