Computer Science 9618/31 — May/June 2021
Cambridge A-Level · Advanced Theory · worked solutions for every part, with the mark scheme
Topics Data Representation · System Software · Computational Thinking and Problem-solving · Artificial Intelligence (AI) · Communication and Internet Technologies · Hardware and Virtual Machines · +1 more
Real numbers are stored in a computer system using floating-point representation with:
• 10 bits for the mantissa
• 6 bits for the exponent
• Two’s complement form for both the mantissa and the exponent.
Calculate the normalised floating-point representation of –7.25 in this system.
Show your working.
| Mantissa | Exponent | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Calculate the denary value of the given binary floating-point number.
Show your working.
| Mantissa | Exponent | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 |
The given binary floating-point number is not normalised.
Normalise the floating-point number. Show your working.
| Mantissa | Exponent | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
Mantissa
Exponent
The denary number 513 cannot be stored accurately as a normalised floating-point number in this computer system.
Explain the reason for this.
Describe an alteration to the way floating-point numbers are stored to enable this number to be stored accurately using the same total number of bits.
The rest of this paper
8 more questions- Q2Data Representation8M
- Q3System Software9M
- Q4System Software · Computational Thinking and Problem-solving8M
- Q5Artificial Intelligence (AI)8M
- Q6Communication and Internet Technologies4M
- Q7Hardware and Virtual Machines8M
- Q8Computational Thinking and Problem-solving8M
- Q9Further Programming8M