ICT - Unit 5:
Binary
BY: Phuong Nghi 7b2
Table of Contents
Key
Vocab
Binary
Conversion
Text into
Binary
Images
into
Binary
Binary
Addition
Encryption
and
Decryption
Sound
into
Binary
Key vocab
Binary code: a system by which numbers, letters, and
other information are represented using only two
numbers which are 1 (On) and 0 (Off) because the
computer is powered by electricity which can only be
off or on.
Bit: the smallest unit of data that a computer can
process and store (8 bits= byte)
Encoding and Decoding: translation (converting)
1. Encoding: letters => binary
2. Decoding: binary => letters
Key vocab
Overflow: when the data type used to
store data was not large enough to
hold the data.
overflow
Pixels: the smallest unit of a digital
image or graphic that can be
displayed.
Binary Conversion
Binary: 2 numbers (1 and 0)
Denary: decimals
1. Draw the binary conversion table, always write 1 on the right
2. 15 as an example - start from 128 then keep going to the left to see if any number that
15 can subtract without making a negative
3. As we can see that 15 can
minus 8 which is 7 as a
leftover then 7 minus 4
which gives 3, then 3
continue to minus 2 will give
1 and 1 minus 1 is 0.
Binary Conversion
Binary: 2 numbers (1 and 0)
Denary: decimals
4. If the number can minus the bits then we put a 1 under the number, if not then a 0.
5. So the binary code for
15 is 00001111 or you can
simplify it into 1111
(remove the Infront 0s)
6. To check if is it correct then
we put the binary code into the
conversion table. Add all
numbers that has a 1 under it
will give you the answer. In this
case, 8+4+2+1=15!
7. To convert from
binary to denary you just
need to put the binary
code into a conversion
table and do the same
as I mentioned
Binary
Addition
4 important rules:
1. 0+1=1
2. 0+0=0
3. 1+1=0 overflow 1
4. 1+1+1=1 overflow 1
Always start to
calculate from the
right to the left
Remember that like in
decimal addition, the last
carry just makes the number
bigger and is added on to
the left of the number.
Encryption and Decryption
Encryption and Decryption: security (Algorithm + key)
Encryption: normal => secure
Decryption: secure => normal
The algorithm is the
method that you use to
hide your data.
The key is the code that
you use in the algorithm to
keep your message secret.
Example
Algorithm:
Step 1: Copy the encrypted message into the first row.
Step 2: Copy the key into the second row, and keep repeating it until the
end.
Step 3: For each bit in the third row, if the two bits above it are the same
(both white or both black), color it black. Otherwise, leave it white.
Text => Binary
We use ASCII or Unicode
Example: Letter T - 01110100
1. Add those number
with a 1 under:
64+32+16+4= 116
2. Find 116 on the ASCII
table to check the
answer
Image => Binary
Pixels RGB - Red, Green, Blue
(255,255,255) =>
Why 255?
Each pixel in an
Red+Green+Blue = White Because
image is made up of
1+2+4+8+16+32+64+128 binary numbers
=255 (Maximum color)
Waves! The higher the bitrate the more data there is in
each frame => the better the quality of sound
Sound => Binary