ACT Preparation / Unit 7 ACT 0602 short lesson, about 20 seconds
Rational and Irrational Numbers
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The idea
A rational number is a fraction of two integers with a nonzero denominator, and its decimal terminates or repeats. An irrational number's decimal never ends and never repeats, like √2 or π.
In practice
3/8 = 0.375 terminates; 2/11 = 0.1818… repeats; both are rational.
Where people slip
Not every square root is irrational: √49 is 7, an integer.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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