Security

Your old mobile phone number could compromise your cybersecurity

The Department of Computer Science and Center for Information Technology Policy at Princeton University has conducted a study and released a paper assessing the security and privacy risks of phone number recycling by mobile ...

Computer Sciences

Algorithm quickly simulates a roll of loaded dice

The fast and efficient generation of random numbers has long been an important challenge. For centuries, games of chance have relied on the roll of a die, the flip of a coin, or the shuffling of cards to bring some randomness ...

Computer Sciences

Securing the 'internet of things' in the quantum age

MIT researchers have developed a novel cryptography circuit that can be used to protect low-power "internet of things" (IoT) devices in the coming age of quantum computing.

Software

Confide off-the-record app comes to Android

(Phys.org) —Ask any teenager trading selfies and very random thoughts: Some messages unlike diamonds should best be not forever. Confide, a company that makes an app with the same name, thinks that business people have ...

Computer Sciences

How randomly moving electrons can improve cyber security

In October 2017, tech giant Yahoo! disclosed a data breach that had leaked sensitive information of over 3 billion user accounts, exposing them to identity theft. The company had to force all affected users to change passwords ...

Machine learning & AI

Physical systems perform machine-learning computations

You may not be able to teach an old dog new tricks, but Cornell researchers have found a way to train physical systems, ranging from computer speakers and lasers to simple electronic circuits, to perform machine-learning ...

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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