15 MOST COMMONLY USED
RATIONAL NUMBERS
FRACTION DECIMAL
EXAMPLES OF
IRRATIONAL
NUMBERS
1
2
1
3
2
3
1
4
NUMBER
3
4
𝝅
3.141593 . . .
𝟏𝟑
3.605551 . . .
𝟐
1.414214 . . .
(To 6 places)
1
5
2
5
3
5
DECIMAL
Can you find 3 irrational numbers? 4
5
1
6
5
6
1
8
3
8
History of Irrational Numbers
Apparently Hippasus (one of Pythagoras' students) discovered irrational
numbers when trying to represent the square root of 2 as a fraction (using
geometry, it is thought). Instead he proved you couldn't write the square root
of 2 as a fraction and so it was irrational.
5
8
However Pythagoras could not accept the existence of irrational numbers,
because he believed that all numbers had perfect values. But he could not
disprove Hippasus' "irrational numbers" and so Hippasus was thrown
overboard and drowned!
7
8
http://www.mathsisfun.com/irrational-numbers.html