(Britain) Either of a pair of rectangular metal plates bearing an alphanumeric code, fixed to the front and rear of a motor car to show its identity as registered with the DVLA.

plural of telephone number

(physics, chemistry) The number of protons in an atom. Symbol: Z

(mathematics) The set of positive integers, {1, 2, 3, ...}. / (mathematics, computer science) The set of non-negative integers, {0, 1, 2, 3, ...}.

(mathematics) a positive integer {1, 2, 3, ...} / (mathematics) a non-negative integer {0, 1, 2, ...}

plural of rational number

plural of real number

(complex analysis) A number of the form a + bi, where a and b are real numbers and i denotes the imaginary unit

(mathematics) The smallest set containing all limits of convergent sequences of rational numbers.

(mathematics) The set of numbers that can be expressed as a ratio of integers, often denoted with the bold letter Q, or the blackboard bold letter ℚ.