Central processing unit (CPU)
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which part of a digital system carries out program instructions and processes data?
2. Which description of the CPU is correct?
3. How does a CPU work through a program?
4. A faster CPU usually means a computer will...
5. True or false: The CPU processes data.
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1CPU | AA faster CPU speed means tasks run faster. A slower CPU takes longer to carry out instructions. | |
| 23.5 GHz | BThe CPU does not store files. It processes data and runs instructions. Storage devices such as a hard drive or SSD keep files permanently. | |
| 3The CPU follows instructions one after another, in order | Cfetch -> decode -> execute | |
| 4The CPU processes data in the input, process, output flow | DA measure of CPU processing speed: how many cycles it can run each second | |
| 5The CPU is where all files are kept permanently | Einput -> CPU -> output | |
| 6A slower CPU makes tasks run faster | FThe central processing unit, the 'brain' of a digital system that carries out program instructions and processes data |
C
Definitions
CPU
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
The ___ is the brain of the system
2.
instructions = ["add", "save", "show"]
CPU.run(instructions[_])
3.
___ instruction in program:
CPU.run(instruction)
4.
isFast = cpuSpeed _ 2.0
5.
result = CPU._______(data)
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
steps = ["add", "save"]
B
for s in steps
C
print("CPU runs", s)
Question 2
A
speed = 2
B
tasks = 8
C
time = tasks / speed
D
Print("Time taken:", time)
Question 3
A
speed = 4
B
work = 12
C
time = work * speed
D
print("Seconds:", time)
Question 4
A
step == 1
B
while step <= 3:
C
print("Run step", step)
D
step = step + 1
Question 5
A
number = 5
B
doubled = number / 2
C
print("Result:", doubled)
Answer Key
Central processing unit (CPU)
Section A: Quick Questions
Q1
A — The CPU
Q2
B — It is the 'brain' of a digital system
Q3
B — It follows instructions one after another
Q4
A — Run tasks more quickly
Q5
A — True
Section B: Match the Pairs
Q1
CPU → The central processing unit, the 'brain' of a digital system that carries out program instructions and processes data
Q2
3.5 GHz → A measure of CPU processing speed: how many cycles it can run each second
Q3
The CPU follows instructions one after another, in order → fetch -> decode -> execute
Q4
The CPU processes data in the input, process, output flow → input -> CPU -> output
Q5
The CPU is where all files are kept permanently → The CPU does not store files. It processes data and runs instructions. Storage devices such as a hard drive or SSD keep files permanently.
Q6
A slower CPU makes tasks run faster → A faster CPU speed means tasks run faster. A slower CPU takes longer to carry out instructions.
Section C: Definitions
Q1
CPU — The central processing unit is the 'brain' of a digital system. It carries out program instructions one after another and processes data. Its speed affects how fast tasks run.Section D: Fill in the Blanks
Q1
The CPU is the brain of the systemQ2
instructions = ["add", "save", "show"]
CPU.run(instructions[0])Q3
for instruction in program:
CPU.run(instruction)Q4
isFast = cpuSpeed > 2.0Q5
result = CPU.process(data)Section E: Spot the Error
Q1
B — A for loop line must end with a colon. The CPU works through each step one after another, so the loop line should be: for s in steps:
Q2
D — Python is case sensitive, so Print with a capital P does not exist. It should be print("Time taken:", time).
Q3
C — A faster CPU finishes work in less time, so time must be work divided by speed. It should be time = work / speed, not multiplied.
Q4
A — A single = stores a value in a variable, but == only compares values. To set the starting step, write step = 1.
Q5
B — The CPU processes data using instructions. Dividing by 2 halves the number instead of doubling it. It should be doubled = number * 2.