Unit 03
🔢 High-Scoring Topic
Data Representation
in Computers
Investigate how all data — numbers, text and instructions — is stored using just two states (0 and 1). Master number system conversions, signed integer representations (2's complement), character encoding schemes and binary arithmetic operations. Covers competency levels 3.1–3.3 from the NIE ICT syllabus.
⚡ Binary Number System
🔷 Octal Number System
🔶 Hexadecimal System
🔄 Base Conversions
➕ Signed Magnitude
🔁 1's Complement
✅ 2's Complement
📝 BCD & EBCDIC
🔤 ASCII Encoding
🌐 Unicode (UTF-8/16)
➕ Binary Addition
➖ Binary Subtraction
⚙️ Bitwise Logic Operations
📚 Competency Levels — Unit 03
COMPETENCY 3.1 · 10 PERIODS
Number Representation
Binary, octal and hexadecimal systems. Conversions between all bases. Signed integer representations: signed magnitude, one's complement and two's complement. MSB as sign indicator.
COMPETENCY 3.2 · 4 PERIODS
Character Representation
BCD, EBCDIC, ASCII (7-bit & 8-bit) and Unicode. Converting symbols into each scheme. Advantages and disadvantages of each representation method.
COMPETENCY 3.3 · 4 PERIODS
Binary Arithmetic & Logic
Binary addition (with carryovers, multiple numbers) and subtraction (with borrowing). Bitwise logical operations: NOT, AND, OR and XOR on binary values.
📊 Number System Quick Reference
| Decimal | Binary (Base 2) | Octal (Base 8) | Hexadecimal (Base 16) |
|---|---|---|---|
| 0 | 0000 | 0 | 0 |
| 1 | 0001 | 1 | 1 |
| 2 | 0010 | 2 | 2 |
| 3 | 0011 | 3 | 3 |
| 4 | 0100 | 4 | 4 |
| 5 | 0101 | 5 | 5 |
| 6 | 0110 | 6 | 6 |
| 7 | 0111 | 7 | 7 |
| 8 | 1000 | 10 | 8 |
| 9 | 1001 | 11 | 9 |
| 10 | 1010 | 12 | A |
| 11 | 1011 | 13 | B |
| 12 | 1100 | 14 | C |
| 13 | 1101 | 15 | D |
| 14 | 1110 | 16 | E |
| 15 | 1111 | 17 | F |
📥 Unit 03 — Available Downloads
📄
Full Notes — Data Representation
PDF · 3.6 MB · 50 pages
📄
Number Conversion Worksheet
PDF · 1.2 MB · 14 pages
📄
2's Complement & Signed Numbers
PDF · 1.0 MB · 10 pages
📄
ASCII & Unicode Reference Sheet
PDF · 0.7 MB · 4 pages
📄
Binary Arithmetic Practice
PDF · 0.9 MB · 8 pages