Transcript Course overview

Data quantity – how much data?
Skills: none
Concepts: the quantity of data as measured in bits or
bytes, prefixes for large numbers, abbreviation
conventions, data ≠ information
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Where does this topic fit?
• Internet concepts
– Applications
– Technology
– Implications
• Internet skills
– Application development
– Content creation
– User skills
All data is binary
010101011100101010101010101010111010
101010101010101010101010100101010101
000010110101010101010010101101101010
101010110010110010101010100101110101
001010010101010101010001001010101011
010011010010101010100101101001011100
101010101001010101000101010101010101
010010101001010101001001001001010101
001000101010101110100101001010101010
010101010101001010100100101010010101
001001010101001010100101010100101010
101001010101011110101011100001111011
The bit – the smallest amount of data
0
1
One bit can contain information
1 → Male
0 → Female
Numeric prefixes – exact and close enough
Prefix
Means
Exact value
kilo
1024^1
1,024
mega
1024^2
1,048,576
giga
1024^3
1,073,741,824
tera
1024^4
1,099,511,627,776
Prefix
Means
Close enough
Decimal name
kilo
1000^1
1,000
thousand
mega
1000^2
1,000,000
million
giga
1000^3
1,000,000,000
billion
tera
1000^4
1,000,000,000,000
trillion
Why 1,024?
Decimal numbers, 10 symbols:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Binary numbers, 2 symbols:
0, 1
Decimal
Binary
0
1
2
4
8
16
32
64
128
256
512
1,024
Round number
0
1
10
100
1000
10000
100000
1000000
10000000
100000000
1000000000
10000000000
1,000
Funky number
1111101000
A byte is 8 bits
1
0
0
1
0
1
0
1
Abbreviations
Prefix
Bits
Bytes
K
Kb
KB
M
Mb
MB
G
Gb
GB
T
Tb
TB
Without a calculator …
How many bits in 1,400 bytes?
Which is more – 1 megabit or 100 KB?
Memory and storage capacity
What is the capacity of your computer’s memory? Storage device?
Do you know how to find out?
Memory capacity
Storage capacity
How bits can encode information – a punch card example
1 → Hole
0 → No hole
So, there are two ones (punched holes) in this card.
The card has 12 rows and 80 columns -- how may 0s are there?
What is the total storage capacity of a punched card?
Punch cards used a 0/1 code for text
See your name in a punch
card using the keypunch
emulator at kloth.net.
What is the code for the
letter X? Y?
Data ≠ Information
Summary
0
1
How much data?
Self-study questions
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How many dollars is one megapenny?
How many dollars is 1.5 megapennies?
We call 8 bits a byte – what do we call 10 pennies?
How many eggs in 17 dozen?
What is the capacity of your computer’s storage device?
What is the capacity of your computer’s memory?
How many bits will an 8GB flash drive hold?
Which requires more storage – a 1Mb text file or a 1Mb image file?
How many bytes in a 27,503 bit file?
How many bits in a 27,503 byte file?
Which would take longer to transmit across the Internet – a 1Mb text file or a 1Mb image file?
At 10 Mb per second, how long will it take to transfer a 20 Mb file across the Internet?
At 10 Mb per second, how long will it take to transfer a 20 MB file across the Internet?
At 10 Mb per second, how long will it take to transfer a 2 Mb file across the Internet?
At 10 Mb per second, how long will it take to transfer a 2 MB file across the Internet?
At 10 MB per second, how long will it take to transfer a 20 Mb file across the Internet?
At 10 MB per second, how long will it take to transfer a 20 MB file across the Internet?
At 10 MB per second, how long will it take to transfer a 2 Mb file across the Internet?
At 10 MB per second, how long will it take to transfer a 2 MB file across the Internet?
Create a spreadsheet that can convert data quantities (see the calculator on the next slide).
Create a spreadsheet to compute data transmission times given transmission speed and file size.
You can count and do arithmetic in binary or decimal – what are the advantages and
disadvantages of each?
Resource
Data quantity conversion calculator:
http://www.matisse.net/bitcalc/