Security

Journalists, activists ensnared in Israeli spyware scandal

European politicians and media groups voiced outrage Monday over reports that an Israeli firm supplied phone malware used by governments to spy on activists, journalists, lawyers and politicians in several countries.

Security

Pegasus spyware: how does it work?

Governments around the world are facing bombshell allegations that they used Israeli-made malware to spy on the phones of activists, journalists, corporate executives and politicians.

Consumer & Gadgets

Scrambling against smudge attacks

The security-conscious among us use a PIN, a personal identification number, to "lock" our smartphones so that if the device is lost or stolen, a third party should not be able to access our contacts, messages, and other ...

page 1 from 14

Number

A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Mathematical operations are certain procedures that take one or more numbers as input and produce a number as output. Unary operations take a single input number and produce a single output number. For example, the successor operation adds one to an integer, thus the successor of 4 is 5. Binary operations take two input numbers and produce a single output number. Examples of binary operations include addition, subtraction, multiplication, division, and exponentiation. The study of numerical operations is called arithmetic.

A notational symbol that represents a number is called a numeral. In addition to their use in counting and measuring, numerals are often used for labels (telephone numbers), for ordering (serial numbers), and for codes (e.g., ISBNs).

In common use, the word number can mean the abstract object, the symbol, or the word for the number.

This text uses material from Wikipedia, licensed under CC BY-SA