Numbers in Computer science

What is the ACSII code?

ASCII ( abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Most modern character-encoding schemes are based on ASCII, although they support many additional characters. For every character, there is an ASCII code. (Or one can say for every symbol, letter, etc, there is a combination of characters corresponding to it.

What are floating point numbers?

As the name implies, floating point numbers are numbers that contain floating decimal points. For example, the numbers 5.5, 0.001, and -2,345.6789 are floating point numbers. Numbers that do not have decimal places are called integers. Computers recognize real numbers that contain fractions as floating point numbers. When a calculation includes a floating point number, it is called a "floating point calculation." Older computers used to have a separate floating point unit (FPU) that handled these calculations, but now the FPU is typically built into the computer's CPU.

What are integers in computer science?

In computer science, an integer is a datum of integral data type, a data type that represents some range of mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are commonly represented in a computer as a group of binary digits (bits). The size of the grouping varies so the set of integer sizes available varies between different types of computers

What is a binary number?

In mathematics and digital electronics, a binary number is a number expressed in the base-2 numeral system or binary numeral system, which uses only two symbols: typically "0" (zero) and "1" (one).

What is bit?

The bit is a basic unit of information in information theory, computing, and digital communications. The name is a portmanteau of binary digit. In information theory, one bit is typically defined as the information entropy of a binary random variable that is 0 or 1 with equal probability, or the information that is gained when the value of such a variable becomes known As a binary digit, the bit represents a logical state, having only one of two values. It may be physically implemented with a two-state device. These values are most commonly represented as either 0or1, but other representations such as true/false, yes/no, +/−, or on/off are common.

How to use two's complement for binary addition?

The first character still indicates the sign. However, we don't have a negative 0. Instead, we go to -8 at the negative (for example, one extra negative symbol in the end)

What does signed and unsigned mean in CS?

The term "unsigned" in computer programming indicates a variable that can hold only positive numbers. The term "signed" in computer code indicates that a variable can hold negative and positive values. The property can be applied to most of the numeric data types including int, char, short, and long.

What is double and single precision in floating numbers?

The term double precision is something of a misnomer because the precision is not really double.The word double derives from the fact that a double-precision number uses twice as many bits as a regular floating-point number.For example, if a single-precision number requires 32 bits, its double-precision counterpart will be 64 bits long. The extra bits increase not only the precision but also the range of magnitudes that can be represented.The exact amount by which the precision and range of magnitudes are increased depends on what format the program is using to represent floating-point values.Most computers use a standard format known as the IEEE floating-point format. The IEEE double-precision format actually has more than twice as many bits of precision as the single-precision format, as well as a much greater range. The IEEE single precision floating point standard representation requires a 32 bit word, which may be represented as numbered from 0 to 31, left to right. The IEEE double precision floating point standard representation requires a 64 bit word, which may be represented as numbered from 0 to 63, left to right.

How to convert from decimal to binary?

We start dividing our decimal number by the base number. If there is no remainder we write 0. If there is a remainder we write 1. The numbers should be equal on both sides. When we are done, we read the binary number in reverse order. The same process apply for other bases. We just write down the reminder on the side and write it in reverse and that's the number in our new base.