Choosing a suitable output device for a context

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. A teacher wants to show a video to a hall of 200 students. Which output device is best?

A A projector, because the image can be enlarged for a big audience

B A laptop LCD screen, because it is cheap to run

2. A company needs 500 copies of a black and white report every day at low cost per page. Which is the better choice?

A A laser printer, because it prints fast and each page is cheap

B A 3D printer, because it prints in layers

3. An engineer wants a physical prototype of a new phone case to hold and test. Which output device should be used?

A An inkjet printer, because it prints high quality photos

B A 3D printer, because it builds a solid object layer by layer

4. A smart home needs to tell a blind user that someone is at the door. Which output is most suitable?

A A speaker, because it outputs sound the user can hear

B An LED screen, because it shows a clear image

5. A greenhouse system must open a window when the temperature gets too high. Which output device is needed?

A A speaker, because it makes a loud alarm

B An actuator, because it causes movement

Match the Pairs

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

Left column		Right column
1A school needs a printed class set of 300 worksheets cheaply and quickly		ALaser printer: fast, low cost per page for large print runs
2A teacher must show a lesson to a whole hall of 200 students		BThe claim is wrong and ignores cost and quality needs. An inkjet printer is cheaper to buy and gives good photo quality for light use.
3Result needed is a solid physical model of a new product design, so choose a device that builds objects		CProjector: displays a large image that a big audience can see
4Result needed is physical movement, such as opening a greenhouse window when it gets too hot		D3D printer, because it builds a solid object layer by layer
5A blind user needs spoken directions, so use an LCD screen because it shows clear text		EActuator, because it turns a signal from the microprocessor into movement
6A home user prints a few photos a month, so buy a laser printer because laser printers are always cheapest		FThe result needed is sound, not an image. A speaker should be chosen because it outputs spoken directions.

Definitions

suitable output device

Fill in the Blanks

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

IF need = "3D object" THEN device ← "__________" ENDIF

need ← "movement of a robot arm" device ← "________"

need ← "image for a large audience" device ← "_________"

need ← "100 pages, low cost per page" device ← "_____________"

need ← "sound" OUTPUT "Use a speaker _______ sound is needed"

Spot the Error

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

Question 1

A need ← "sound"

B IF need = "sound" THEN

C device ← "projector"

D ENDIF

Question 2

A IF need = "3D object"

B device ← "3D printer"

C ENDIF

D OUTPUT device

Question 3

A need ← "movement"

B device ← "LCD screen"

C why ← "it makes things move"

D OUTPUT device,"because",why

Question 4

A audience = 300

B IF audience > 100 THEN

C device ← "projector"

D ENDIF

Question 5

A need ← "printed copy"

B IF need = "printed copy" THEN

C device ← "laser printer"

D ENDWHILE

E OUTPUT device

Answer Key

Choosing a suitable output device for a context

Section A: Quick Questions

A — A projector, because the image can be enlarged for a big audience

A — A laser printer, because it prints fast and each page is cheap

B — A 3D printer, because it builds a solid object layer by layer

A — A speaker, because it outputs sound the user can hear

B — An actuator, because it causes movement

Section B: Match the Pairs

A school needs a printed class set of 300 worksheets cheaply and quickly → Laser printer: fast, low cost per page for large print runs

A teacher must show a lesson to a whole hall of 200 students → Projector: displays a large image that a big audience can see

Result needed is a solid physical model of a new product design, so choose a device that builds objects → 3D printer, because it builds a solid object layer by layer

Result needed is physical movement, such as opening a greenhouse window when it gets too hot → Actuator, because it turns a signal from the microprocessor into movement

A blind user needs spoken directions, so use an LCD screen because it shows clear text → The result needed is sound, not an image. A speaker should be chosen because it outputs spoken directions.

A home user prints a few photos a month, so buy a laser printer because laser printers are always cheapest → The claim is wrong and ignores cost and quality needs. An inkjet printer is cheaper to buy and gives good photo quality for light use.

Section C: Definitions

suitable output device — Match the result needed (image, print, sound, 3D, movement) and the situation to the device that suits it best, then justify with 'because'.

Section D: Fill in the Blanks

IF need = "3D object" THEN
  device ← "3D printer"
ENDIF

need ← "movement of a robot arm"
device ← "actuator"

need ← "image for a large audience"
device ← "projector"

need ← "100 pages, low cost per page"
device ← "laser printer"

need ← "sound"
OUTPUT "Use a speaker because
 sound is needed"

Section E: Spot the Error

C — A projector only shows images and cannot produce sound. When the result needed is sound, the device should be a speaker.

A — The IF statement is missing THEN. It should be IF need = "3D object" THEN.

B — An LCD screen displays images and cannot make anything move. A need for movement is met by an actuator, so the line should be device ← "actuator".

A — Pseudocode assigns a value with the arrow ←, not =. It should be audience ← 300.

D — An IF statement must be closed with ENDIF, not ENDWHILE. Line 4 should be ENDIF.