8th Grade · The Number System
Irrational Number
8.NS.A.1
Definition
A number whose decimal form never terminates and never repeats. It cannot be written as a fraction of two integers.
Examples
- Pi = 3.14159265... — the digits never repeat.
- Square roots of non-perfect-squares are irrational, like √2, √3, √5.
Key rule
Rational decimals stop or repeat; irrational decimals never do either.
Memory hook
Never ends, never repeats, never a fraction.