This document discusses digital representation and binary conversion. It defines a bit as the basic unit of data in computing and explains how ASCII uses binary codes to represent letters, numbers, and characters. It then demonstrates how to convert between decimal and binary numbers through long division and provides an example of converting 25 to its binary equivalent of 11001. Finally, it includes tables defining bytes, kilobytes, megabytes, gigabytes and terabytes in terms of bits and bytes.

1. Computer System Servicing NCII
Carry Out Mensuration and Calculation
Marvin B. Broñoso
ICT / CSS Teacher

2. Learning Outcome
• Understand the meaning of bit and ASCII.
• Calculate and convert Binary to Decimal
and Decimal to Binary.
• Learn the Bit and Binary conversion.
• Demonstrate computation of bits
conversion.

3. Learning Content
• What is bit?
• ASCII Codes.
• Conversion of Decimal to binary
• Conversion of Binary to Decimal
• Conversion of Byte and Bit

4. Digital Representation
• In a computer, information is represented
and stored in a digital binary format.
• The term bit(s) is an abbreviation of binary
digit(s), which represent the smallest piece
of data in a computer system.

5. BIT
• A bit can have only two possible values,
which is a one digit (1) or a zero digit (0).
• A bit can be used to represent something
that has two states.
– Example:
• DecisionTrue or False
• Switch On and Off
• Boolean 1 and 0

6. ASCII
• Computer uses binary code to represent
and interpret letters, numbers and special
character with bits.
• A commonly used code is the ASCII
(American Standard Code for Information
Interchange).

7. ASCII
• With ASCII, each character is represented
by a string of bits.
– Example:
• Capital Letter A = 0100 0001
• Number: 9 = 0000 1001
• Special Character: # = 0010 0011

9. ADDITIONAL NOTE:
• Each group of eight bits (8 bits), such as
the representation of letters and numbers,
is known as byte.
8 bits = 1 byte
• Codes can be used to represent almost
any type of information digitally: Computer
data, graphics, photos, voice, video and
music.

10. ADDITIONAL NOTE:
• Each group of eight bits (8 bits), such as
the representation of letters and numbers,
is known as byte.
8 bits = 1 byte
• Codes can be used to represent almost
any type of information digitally: Computer
data, graphics, photos, voice, video and
music.

11. CONVERSION OF DECIMAL TO BINARY
To convert a decimal number to binary, all you
have to do is divide the number by 2.
• Get the quotient and the remainder.
• Bring down the quotient, divide it by
two, and get the quotient and
remainder again.
• Do it repeatedly until the quotient
results become 0.
• Copy the remainder from bottom to top,
and that is the binary equivalent.

12. EXAMPLE
Convert 25 to binary
25 = 11001
QUOTIENT REMAINDER
25 / 2 12 1
12/2 6 0
6/2 3 0
3/2 1 1
1/2 1 1

13. HOW TO CHECK
Checking if 25 = 11001
1 1 0 0 1 multiplier
16 8 4 2 1 equivalents
16 + 8 + 0 + 0 + 1
results
16 + 8 + 1 = 25

15. Bytes Conversion Table
Data storage and when describing memory size, a Kilobyte is
2^10, or 1024 bytes.
Bytes are always some multiple or exponent of two.
1 byte (B) = 8 bits (b)
1 Kilobyte (K / KB) = 2^10 bytes = 1,024 bytes
1 Megabyte (M / MB) = 2^20 bytes = 1,048,576 bytes
1 Gigabyte (G / GB) = 2^30 bytes = 1,073,741,824 bytes
1 Terabyte (T / TB) = 2^40 bytes = 1,099,511,627,776 bytes

16. Bytes Conversion Table
Although data storage capacity, such as on hard drives, is
generally expressed in binary Megabytes (2^20), most Hard
disk manufacturers, and some newer BIOS, use decimal
megabytes (10^6), which is slightly different and it gets
confusing...
1 byte (B) = 8 bits (b)
1 Kilobyte (K / KB) = 10^3 bytes = 1,000 bytes
1 Megabyte (M / MB) = 10^6 bytes = 1,000,000 bytes
1 Gigabyte (G / GB) = 10^9 bytes = 1,000,000,000 bytes
1 Terabyte (T / TB) = 10^12 bytes = 1,000,000,000,000 bytes

17. Bytes Conversion Table