中文（繁體）
中文（简体）
English
S4 ICT Data Representation, Paper 2: conversions, units and hexadecimal
S4 ICT Data Representation, Paper 2: conversions, units and hexadecimal
Paper 2 moves from binary 1101 giving 13, denary 37 as 00100101, hex 3C giving 60 and two bytes as 16 bits, on to 4 KiB as 4096 bytes, A to C giving 67, 1101 plus 0011 giving 10000, 3 MiB as 3145728 bytes and denary 200 as C8.
Reminders Binary place values are powers of two, each hex digit holds 4 bits, and Ki and Mi each multiply by 1024.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 25 |
| Difficulty mix | Foundation 4 · Intermediate 3 · Challenge 2 · Error redo 1 |
| Chapter | Chapter: S4 ICT: Data Representation |
| Level | S4 |
02 Questions (10 items)
- FoundationWhat is the denary value of the binary number 1101?
- FoundationWhat is denary 37 in 8-bit binary?
- FoundationWhat is the denary value of the hexadecimal number 3C?
- FoundationHow many bits are there in 2 bytes?
- IntermediateHow many bytes are there in 4 KiB?
- IntermediateThe ASCII code of A is 65. What is the ASCII code of C?
- IntermediateAdd the binary numbers 1101 and 0011. What is the binary result?
- ChallengeHow many bytes are there in 3 MiB?
- ChallengeWhat is denary 200 in hexadecimal?
- Error redoError repair: a student said 8 bits can represent 0 to 256, which is 257 values. How many values is it really?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 13 | One times 8 plus one times 4 plus zero times 2 plus one times 1 gives 8 plus 4 plus 1, which is 13. |
| 2 | 00100101 | 37 is 32 plus 4 plus 1, so the bits from left to right read 00100101. |
| 3 | 60 | Three times 16 is 48 and C stands for 12, so the total is 60. |
| 4 | 16 bits | Each byte holds 8 bits, so two bytes are 2 times 8, which is 16 bits. |
| 5 | 4096 bytes | Ki means 1024, so 4 KiB is 4 times 1024, which is 4096 bytes. |
| 6 | 67 | Each following letter adds one, and A to C is two steps, so 65 plus 2 gives 67. |
| 7 | 10000 | 1101 is 13 and 0011 is 3; 13 plus 3 is 16, which in binary is 10000. |
| 8 | 3145728 bytes | Mi means 1024 times 1024, which is 1048576, and times 3 gives 3145728 bytes. |
| 9 | C8 | 200 divided by 16 is 12 remainder 8, and 12 is written C, so the answer is C8. |
| 10 | 0 to 255, which is 256 values | Eight bits give 2 to the power 8, which is 256 combinations, counted from 0 to 255. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Book an S4 ICT tutorTutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
