The Number System (Grade 12 NSC Matric Mathematics): Flashcards

Positive whole numbers for counting: 1, 2, 3, 4, 5, ...

Natural numbers including zero: 0, 1, 2, 3, 4, 5, ...

All whole numbers, positive and negative: ..., -2, -1, 0, 1, 2, ...

Numbers as $\frac{a}{b}$; $a$, $b$ integers, $b \neq 0$

Fractions, terminating decimals, recurring decimals

Cannot be fractions; decimals never terminate or repeat

Set of all rational and irrational numbers combined

Result from square roots of negative numbers

$i = \sqrt{-1}$

Natural ⊂ Whole ⊂ Integers ⊂ Rational ⊂ Real