(quantum mechanics) One of certain integers or half-integers that specify the state of a quantum mechanical system (such as an electron in an atom).

A number written in the form a × bᶜ, e.g. 3.75 × 10³ (a being the mantissa, b, the base and c, the exponent).

(physics, chemistry) The total number of protons and neutrons in an atomic nucleus. Symbol: A

(computing) A number represented by the binary digits 0 and 1.

(mathematics) any irrational number that is not an algebraic number

(set theory) Any cardinal or ordinal number which is larger than any finite, i.e. natural number; often represented by the Hebrew letter aleph (ℵ) with a subscript 0, 1, etc.

A number whose decimal representation ends in one or more zeroes. / A rough approximation, especially one whose decimal representation ends in one or more zeroes.

A unique number, assigned to a particular unit of some product, to identify it.

(mathematics) A number expressed in the decimal system (base ten), (particularly) fractional numbers so represented.

(algebra, number theory) A complex number (more generally, an element of a number field) that is a root of a polynomial whose coefficients are integers; equivalently, a complex number (or element of a number field) that is a root of a monic polynomial whose coefficients are rational numbers.