Sub-system

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which statement describes a sub-system?

A A smaller part of a system that does one job

B The whole computer system with all its parts

2. Which of these is a sub-system of a computer?

A The CPU

B The whole computer

3. What is the job of the memory sub-system in a computer?

A To hold data and instructions the computer is using now

B To process every instruction in the whole computer

4. A computer system is made up of the CPU, memory and storage. What are the CPU, memory and storage called?

A Whole systems

B Sub-systems

5. True or false: a sub-system does many unrelated jobs for the whole system.

A True: it does many unrelated jobs

B False: it does one job

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1CPU		AThis reverses the relationship. The CPU is a sub-system of the computer, not the other way round.
2Storage		BMemory sub-system -> holds data and instructions being used
3A sub-system is a smaller part of a system that does one job		CA sub-system is only one smaller part of the system, not the whole system.
4The whole system is made up of its sub-systems working together		DComputer = CPU + Memory + Storage
5The computer is a sub-system of the CPU		EA sub-system of a computer that processes instructions, doing just that one job within the whole system
6A sub-system is the whole computer system		FA sub-system of a computer that keeps data and programs permanently, even when the power is off

Definitions

sub-system

Fill in the Blanks

Complete each line of code by filling in the missing parts.

computer = ___ + memory + storage

sub-system _______: keeps files when off

computer = whole, CPU = __________

A sub-system is ___ the whole system

Each sub-system does ___ job

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A System ← "CPU"

B Part1 ← "CPU"

C Part2 ← "Memory"

D Part3 ← "Storage"

Question 2

A PROCEDURE ShowCPU()

B OUTPUT "CPU: processes data"

C OUTPUT "It is one part"

D ENDFUNCTION

Question 3

A OUTPUT "Computer parts:"

B OUTPUT "CPU: processes data"

C OUTPUT "Memory: keeps files"

D OUTPUT "Storage: keeps files"

Question 4

A INPUT Part

B IF Part = "CPU"

C OUTPUT "Sub-system"

D ENDIF

Question 5

A PROCEDURE Storage()

B OUTPUT "Saves files"

C OUTPUT "Does every job"

D ENDPROCEDURE

Answer Key

Sub-system

Section A: Quick Questions

A — A smaller part of a system that does one job

A — The CPU

A — To hold data and instructions the computer is using now

B — Sub-systems

B — False: it does one job

Section B: Match the Pairs

CPU → A sub-system of a computer that processes instructions, doing just that one job within the whole system

Storage → A sub-system of a computer that keeps data and programs permanently, even when the power is off

A sub-system is a smaller part of a system that does one job → Memory sub-system -> holds data and instructions being used

The whole system is made up of its sub-systems working together → Computer = CPU + Memory + Storage

The computer is a sub-system of the CPU → This reverses the relationship. The CPU is a sub-system of the computer, not the other way round.

A sub-system is the whole computer system → A sub-system is only one smaller part of the system, not the whole system.

Section C: Definitions

sub-system — A smaller part of a computer system that does one job within the whole system, such as the CPU, memory or storage in a computer. It is not the whole system.

Section D: Fill in the Blanks

computer = CPU + memory + storage

sub-system storage: keeps files when off

computer = whole, CPU = sub-system

A sub-system is not the whole system

Each sub-system does one job

Section E: Spot the Error

A — The whole system is the computer. The CPU is only one sub-system inside it. Line 1 should be System ← "Computer".

D — A PROCEDURE must be closed with ENDPROCEDURE, not ENDFUNCTION.

C — Memory holds data that is currently in use. Keeping files long term is the job of the storage sub-system. Each sub-system does its own job.

B — An IF statement needs the keyword THEN after the condition. It should be IF Part = "CPU" THEN.

C — A sub-system does one job, not every job. The line should say that storage has one job only.