Data Representation Flashcards
1
Q
What is a natural number?
A
- All positive whole numbers and zero
- Can be used for counting
- N = {0,1,2,3,…}
2
Q
What is an integer?
A
- Whole numbers
- Positive and negative including zero
- Z = {…,-2,-1,0,1,2,…}
3
Q
What are rational numbers?
A
- A number that can be expressed as a fraction
- Can be positive or negative
- Zero is a rational number
- The symbol for rational numbers is Q
4
Q
What are irrational numbers?
A
- Cannot be written exactly as a fraction
- They have no symbol
- Examples include π or √ 2
5
Q
What are real numbers?
A
- All possible real world quantities
- All members of irrational, rational, integers and natural numbers are real numbers
- Given the symbol R
6
Q
What are ordinal numbers?
A
- Integers used to describe the numerical positions of objects in relation to others
7
Q
What is the decimal number base?
A
- Base 10
- Used by humans for counting
- Uses the ten digits 0 through 9 to represent numbers
- Often called denary
8
Q
What is the binary number base?
A
- Base 2
- Uses only two characters for each digit, either a 1 or 0
9
Q
What is the hexadecimal number base?
A
- Base 16
- Uses the digits 0 through 9 and A to F
10
Q
Why is hexadecimal useful as a shorthand representation for binary?
A
- Can represent numbers using far fewer digits than binary or decimal
11
Q
What is a bit?
A
- The fundamental unit of information
- Only takes two values, a 1 or 0
12
Q
What is a byte?
A
- A collection of 8 bits
13
Q
What is a nibble?
A
- A collection of 4 bits, half a byte
14
Q
How many values can be represented with n bits?
A
- 2^n values can be represented
15
Q
What are the binary prefixes for quantities of bytes?
A
- Kibi (Ki) = 2^10
- Mebi (Mi) = 2^20
- Gibi (Gi) = 2^30
- Tebi (Ti) = 2^40
16
Q
What are the decimal prefixes for quantities of bytes?
A
- Kilo (K) = 10^3
- Mega (M) = 10^6
- Giga (G) = 10^9
- Tera (T) = 10^12
17
Q
What is underflow?
A
- Occurs when very small numbers are to be represented but there are not enough bits available
18
Q
What is overflow?
A
- Occurs when a number is too large to be represented with the available bits
19
Q
What is ASCII?
A
- Stands for American Standard Code for Information Interchange
- Uses 7 bits to represent 128 (2^7) different characters
20
Q
How did ASCII become outdated?
A
- With the advent of the Internet, there was a requirement for an information coding system that could represent character sets other than the Latin alphabet, such as Greek or Arabic
- ASCII did not have enough bits to represent all of these character sets
21
Q
What is Unicode?
A
- Allows the representation of a wide variety of alphabets by computers
- Uses anywhere from 8 to 48 bits per character
- Represents a much wider range of different characters than ASCII
22
Q
What is a parity bit?
A
- Form of error checking
- A single bit is added to transmission
- This bit is used to check for errors in the transmitted data
- The bit’s value is calculated based on the transmitted data itself
23
Q
What is even parity?
A
- The parity bit makes the total number of 1s in the transmitted data even
24
Q
What is odd parity?
A
- The parity bit makes the total number of 1s in the transmitted data odd
25
Q
What happens if an error is detected in using parity?
A
- The computer asks the sender to retransmit the data
