# 3 Fundamentals Of Data Representation Flashcards

What is the capacity of a device?

The capacity of a device is how much data it can store

Why is it important to know the units of capacity of a device?

It is important to know the units of capacity so that we can compare the capacity of different devices

What is a bit?

A bit is the smallest amount of data that we can store. It is a binary digit, often called a bit for short.

The value can only be either a 0 or 1

Why don’t we use bits to measure data?

The bit is too small for measuring data

How large is a nibble?

4 bits

How large is a Byte?

8 bits

What are the most common units for comparing storing data?

Kilobyte (KB) (1000 bytes).

Megabyte (MB) (1000 KB).

Gigabyte (GB) (1000 MB).

Terabyte (TB) (1000 GB).

What are the three things required to calculate the amount of data that can be stored within a certain capacity?

The three things required to calculate data required storage in a capacity are:

- Size of data being stored
- Available Capacity
- How to convert between units

Why is it important to know the size of data being stored?

The bigger the size of the data being stored, the bigger capacity media will be needed

Why is it important to know the available capacity of our device?

The more capacity available, the more data we can store

Why is it important to know how to convert between units?

To find out if we have enough capacity, it is important to put the capacity of the media and the size of the data into the same units

What is the equation to calculate required capacity of a device?

Required capacity = number of files × size of a single file

What is Denary?

Denary is our number system where we use 10 symbols to represent each digit

What is Binary?

Binary is a number system where only the digits zero and one are used.

Each digits place is multiplied by 2 as we move from right to left.

What is hexadecimal?

Hexadecimal uses 16 different symbols for each place. Hexadecimal uses the digits 0-9 and A-F

Each digits place value is multiplied by 16 as we move from right to left

How do you convert binary into hexadecimal?

First, you split the binary into groups of 4 bits, starting from the right

You then convert each group separately and put the digits together

How do you convert hexadecimal to denary?

To convert from hexadecimal to denary, you should:

Write out the powers of 16 above each hexadecimal digit.

For each place column, multiply the hexadecimal digit by the power of 16 above it.

Add together all of these results.

What are overflow errors?

If a number is carried past the last place column during binary arithmetic, then this is called an overflow error

What do overflow errors lead to?

Overflow errors can lead to inaccurate results and software crashes

What is a binary shift?

A binary shift is a technique for performing multiplication or division on a binary number

Extra 0 bits are added to the start or end of the binary number to fill any missing spaces

What is a right binary shift?

A right binary shift is when each digit is moved once place to the right

This has the effect of dividing the number by two

You must take care when performing a right shift that no data is shifted off the right hand side. This can cause a loss of accuracy.

What is a left binary shift?

A left binary shift, is when each digit is moved one place to the left.

This has the effect of multiplying the number by two.

You must take care, when performing a left shift, that there is no overflow error (where we run out of space to store the last digit of the number)

What is text data made up of?

Text data is made up of characters

What is a character set?

A character set is a collection of all the characters that a computer recognises, along with their binary codes

What is included in a character set?

Alphanumeric characters e.g. letters, numbers, and symbols

Special characters e.g. new line

What are the two main character sets in use?

American Standard Code for Information Interchange

Unicode

What does ASCII stand for?

American Standard Code for Information Interchange