Cm VI – Lesson – Flowcharts

Tejas and Jyoti discuss a flowchart that they saw at an interschool quiz competition with Moz.

Inter School competition: Ten individual participants from each school. Champion trophy for a school with 50 stars, Cosolation prizes for schools with more than 40 stars and less than 50 stars. Details of quiz are given below. Best of Luck.

Tejas: The interschool competition gave us this graphical representation about the competition before we attempted the quiz on the computer.

Jyoti: We understood the instructions immediately and we also knew that we should get atleast sixteen correct answers to get five stars for our school.

Moz: This graphical representation is called flowchart. One of the uses of flowcharts is communication. Instead of telling each one of you the procedure and the rules this flowchart has been used to communicate details. Notice the simplicity and ease of communicating to you the rules.

Concept: What is a flow chart?

A flowchart is a graphical representation of a process showing the sequence of steps. The flowchart gives a step-by-step solution of a problem. Various geometrical shaped boxes connected by directional arrows represent the sequence of steps.

Flowcharts can be used for many purposes. For example a flowchart can be drawn to communicate a solution to a problem, rules of playing a game, explaining a concept, classification of data, sequence of steps for a computer program.

Uses of flowchart: Communicate ideas, solutions

Usha: Next to each description of the symbol provide the symbol during DTP.

Tejas: Geometrical figures of different shapes are used in this representation.

Moz: Yes. Let us understand these shapes by discussing the flowchart one by one. Let us start at the beginning.

Tejas: First parellelogram tells us that there are 20 questions.

Moz: Data or information that is available or input is represented using a parallelogram.

Tejas: Next there is an arrow pointing to the square. Looks like arrows show the sequence of flow.

Moz: Correct. The four directional arrows are used to show the next step and the flow of a flow chart.

Jyoti: The text in the rectangle tells us that we should enter our id and then take the quiz.

Moz: This is nothing but the action to be taken and the instructions of taking the quiz. A process, an action, or instructions are provided in a rectangle.

Jyoti: The arrow next points to a diamond. There is a question in the diamond. The question can be answered as 'Yes' or 'No' which is based on the score that we get.

Yes Tejas: 'Yes' and 'No' answers are pointing in different directions.

No

Moz: Sometimes in a proces next step is decided based on the answer of a question. For example in the quiz the certificate and the score given to your school depends on the score that you get in the quiz.

Jyoti: The final result is also given in a parallelogram.

Moz: Right. Parallelogram is used to represent also the output. Earlier we used it to represent the input.

Info:

Flowchart symbols and their purpose
Geometric shape / Purpose
Ellipse / Start, Stop, End, Exit
Parallelogram / Data, Input, output
Rectangle / Action, activity, process
Diamond Yes / To ask a decision question
Arrows / Connected by the arrows to show the flow or sequence of steps in a flowchart.

Moz: Now that you have understood the symbols of a flowchart, work out some examples to understand various purposes for which flowcharts are used. Think about the order in which the steps need to occur, then draw the chart. Draw a flowchart for the following problem, so that a person who goes through the flowchart can learn how to solve a similar problem.

  1. Savani bought a toy for Rs. 325 and sold the same for Rs. 458. Explain how we can find if Savani has made a profit or loss.

Flowchart - How to find profit or loss

Concept: Drawing of a flowchart.

Think of the sequence of steps that need to occur.

Represent each step using the appropriate symbol.

Check that the flow is clearly communicated through the flowchart.

Uses of flowchart: To specify the method of solving a mathematical problem.

Moz: Suppose you have to write a scratch program for the above. Can you do it now.

Tejas: Yes. We can.

Jyoti: So we can also plan a computer program using the flowchart.

Moz: Right. Flowcharts are used to plan the sequence of a program.

Jyoti: Sometimes we need to repeat a sequence. How do we represent this in the flowchart.

Moz: You have to use the directional arrow to make a sequence repeat. Draw a flowchart to read a number and print the table (up to 10). I will show you how to repeat the sequence.

Flowchart of multiplication table for a given number N

Uses of flowchart: To plan the sequence of a computer program

Scratch programs to be written for the above two flowcharts.

Moz: Now let us look at another example. Here is a puzzle. Each one of you draw a flowchart to show how you have solved this puzzle.

Puzzle: How many geese in the flock?

A flock of geese are flying and a single goose flying from the opposite direction cried “ Hello 100 geese!”. The leader of the flock answered “We aren't 100. If you take twice our number and add half our number and add a quarter of our number, and finally add you, the result is 100.” How does the lone goose figure out the number of geese in the flock?

Following is the flowchart of Tejas – How many Geese in the flock?

The first box I feel should be a data box. Maybe we can draw line representation inside the data box. Suggest please?

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Solution of the above:

Q = 4+4+2+1 = 11

Number of geese in a quarter = 99/Q = 99/11 = 9

Total number of geese in the flock = 4 quarters = 4 x 9 = 36

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Jyoti's flowchart for the puzzle – How many Geese are we?

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Solution of the above:

No. of geese in flock = N

2N + ½ N + ¼ N +1 = 100

2N + ½ N + ¼ N = 100 – 1 = 99

(8N + 2N +1N)/4 = 99

11N = 99 x 4

N = (99 x 4)/11 = 9 x 4 = 36

No. of geese in the flock = 36

Uses of Flowcharts: Analyzing and solving Puzzles.

Moz: Good. You have shown two ways of solving a problem with and without algebra. Did you first draw the flowchart or did you solve the problem.

Tejas: I have written the sequence of solving the problem first.

Jyoti: First I found the data that was given. Next, I knew that I have to find N. I used algebra to write the next sequence of solving the problem.

Moz: Good. Now let us consider a game. Do you know the game of snakes and ladders?

Tejas: Yes.

Moz: Ok. Draw a flowchart to show how the game is played.

Tejas and Jyoti draw this flowchart.

Flowchart - Snakes and Ladder game

Uses of flowchart:Graphical representation of instructions – ex: games, building models etc.

Tejas: The flowchart itself can be put into the box of the game so that those who want to play know the rules of the game and can easily understand how they win.

Jyoti: There are so many uses of flowcharts. I will try to teach my brother “classification of .....” with a flow chart.

Moz: Yes. You can use flowcharts to teach and also to learn.

Uses of flowchart: For teaching and learning ( I want to give a science example: Any suggestions?)

Moz: We have seen that some examples where flowcharts are used. There are many more uses of flowcharts and they can be used whenever you feel that you can communicate better with this graphical representation. For example when you are doing a group project you can have a flowchart for the project and a flowchart for each member.

Should I give an example for the above ? Any suggestions? I am also thinking about it.

Uses of flowchart: Communication within a team

Jyoti: Next time when we do a project we will use flowcharts. This is really easy to communicate our ideas and the progress of our work.

Tejas: We are eager to learn another programming language.

Moz: Sure. Next you will be learning BASIC where you can use some of the flowcharts that you have drawn in this lesson.

Chin Chinaki.

Work sheet ideas: for Usha

  1. Provide a flowchart and based on this let the students figure out what needs to be done. This can be a topic that they are familiar with. (Ex: finding if the given numbers are prime numbers).
  2. Remove a few parts of the flowchart and ask the students to fill up the flowchart (you can provide the parts – something like fill in the blanks). (Ex: safety on the internet)
  3. Classification flow chart (can be in science, geography)
  4. Ask them to draw crossing of a road flow chart.
  5. Sorting of given numbers in ascending order.
  6. A flowchart for making tea with sugar without sugar, with milk without milk etc or something like this which has decision making.
  7. A general decision making flow chart for an event.
  8. A flow chart to visit people living in a campus (provide directions based on a range of house numbers) .