Whole (natural) numbers

Natural numbers – numbers, which appear as a result of calculus of single subjects:peoples, animals, birds, trees, different wares and so on. Series of natural numbers:  1,  2,  3,  4,  5,  …  is continued endlessly and is called natural series .

Integers –  natural numbers and zero:  0,  1,  2,  3,  4,  5, … . Concept "integers" is expanded in the section "Rational numbers" of the part "Algebra".