Flowcharts

11.2.1.7 use flow charts to input, process, store and output data in computing systems

Flowcharts

A flowchart is one of the methods for representing an algorithm.

A flowchart is a visual representation of the sequence of steps and decisions needed to perform a process

Symbols of flowchart

Symbol (Shape) Name Purpose

Terminator
Start / Stop

An oval represents start and stop point
Input / Output A parallelogram represents input data or output data
Arrow  An arrow is a connector that shows relationship between the representative shapes
Process (Action) A rectangle represents a process
Decision A diamond indicates a decision
Loop A hexagon the hexagon shows start of loop
Subroutine A predefined process symbol indicates the execution of another subalgorithm

Advantages

  • A great tool to see the sequence of an algorithm.
  • It clearly shows what decisions need to be made along with the inputs and outputs.
  • Just by looking at the flowchart, you can see how simple or complex the algorithm is.

Disadvantages

  • Drawing straight shapes can be time consuming. Although there are special applications only for flowcharts.
  • It is very inconvenient to change the flowchart after completion.
  • Not very useful for very complex and large algorithms.

Questions:

  1. What is a flowchart?
  2. What symbols do you know?
  3. Explain the purpose of each symbols.

Exercises:

Ex. 1

Ex. 2

Ex. 3 (Author: Litvinova Olga - CS teacher of NIS Pavlodar)

Ex. 4

Ex. 5 (Author: Litvinova Olga - CS teacher of NIS Pavlodar)

Ex. 6 

Ex. 6

Tasks Flow Charts for Practical Tasks

 

Exam questions:

Question. A computer is used to control the temperature of liquid entering a manufacturing process. A heater is turned on if the liquid is too cold. The operator has first to set the correct temperature. On a separate piece of paper, draw a flowchart to show how the computer would operate this system. (Marks: 5)
  • input temperature (input box)
  • detect temperature (input box)
  • check temperature against input value(process box)
  • is temperature too low?(decision box)
  • 'Yes' and 'No' exits from decosion box
  • 'Yes' leads to 'turn heater on'
  • 'No' loops back to 'detect temperature'
    • any five of these points
Категория: Flowcharts | Добавил: bzfar77 (07.10.2020)
Просмотров: 98 | Теги: Sequence, Process, Output, Condition, subroutine, Flowchart, Input, Loop | Рейтинг: 5.0/1
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