Introduction to
Flowcharting
Grade 10- ICT
What is a Flowchart?
• A flowchart is a
diagram that depicts
the “flow” of a
program.
• The figure shown here
is a flowchart for
calculating the age.
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Basic Flowchart Symbols
• Notice there are three
types of symbols in this
flowchart:
– rounded rectangles
– parallelograms
– a rectangle
• Each symbol represents
a different type of
operation.
Rounded
Rectangle
Parallelogram
Rectangle
Rounded
Rectangle
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Basic Flowchart Symbols
• Terminals
– represented by rounded
rectangles
– indicate a starting or
ending point
Terminal
START
END Terminal
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Basic Flowchart Symbols
• Input/Output Operations
– represented by
parallelograms
– indicate an input or
output operation
Enter Present
year Display Age
Input/Output
Operation
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Basic Flowchart Symbols
• Processes
– represented by rectangles
– indicates a process such as
a mathematical
computation or variable
assignment
Age = Present
Year- Year of
Birth
Process
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Stepping Through
the Flowchart
Enter the
present
year:
Variable Contents:
Present Year: ?
Year of Birth: ?
Age: ?
Output
Operation
Stepping Through
the Flowchart
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable - a data item that may take on more than one value
during the runtime of a program.
Stepping Through
the Flowchart
Enter the
Present
Year: 2016
Input Operation
(User types 2016)
Stepping Through
the Flowchart
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable Contents:
Present Year: 2016
Year of Birth: ?
Age: ?
Variable - a data item that may take on more than one value
during the runtime of a program.
Stepping Through
the Flowchart
Enter your
Year of
birth:
Output
Operation
Stepping Through
the Flowchart
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable Contents:
Present Year: 2016
Year of Birth: ?
Age: ?
Variable - a data item that may take on more than one value
during the runtime of a program.
Stepping Through
the Flowchart
Enter your
Year of
Birth: 1990
Input Operation
(User types 1990)
Stepping Through
the Flowchart
Variable Contents:
Present Year: 2016
Year of Birth: 1990
Age: ?
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable - a data item that may take on more than one value
during the runtime of a program.
Process: The
difference of
2016 and
1990 is 26
which is
stored as Age
Stepping Through the
Flowchart
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable Contents:
Present Year: 2016
Year of Birth: 1990
Age: 26
Enter your
Year of
Birth: 1990
Variable - a data item that may take on more than one value
during the runtime of a program.
Stepping Through
the Flowchart
Age is 26
Output
Operation
START
Display message
“Enter the
present year”
Read Present
year
Display message
“Enter your year
of birth”
Read Year of
birth
Age = Present
year – Year of
birth
Display Age
END
Variable Contents:
Present Year: 2016
Year of Birth: 1990
Age: 26
Variable - a data item that may take on more than one value
during the runtime of a program.
Sample Problems:
1. Create a flowchart that will get the sum of two integers.
2. Create a flowchart that will convert a peso to dollar.
Exchange rate is $. 1.00 = Php. 45.00 (fixed)
Exercise Problems:
1. Create a flowchart that will convert a Celsius value to
Fahrenheit.
F= C * 9/5 +32
2. Create a flowchart that will get the Average of three
integers.
Four Flowchart Structures
• Sequence
• Decision
• Repetition
• Case
Sequence Structure
• a series of actions are performed in sequence
• The pay-calculating example was a sequence
flowchart.
Decision Structure
• One of two possible actions is taken, depending on a
condition.
Decision Structure
• A new symbol, the diamond, indicates a yes/no question. If
the answer to the question is yes, the flow follows one path.
If the answer is no, the flow follows another path
YESNO
Decision Structure
• In the flowchart segment below, the question “is x < y?” is
asked. If the answer is no, then process A is performed. If the
answer is yes, then process B is performed.
YESNO
Is
x < y?
Process BProcess A
Sample Problem
1. A flowchart that will identify the grade
entered by the user. If the grade is 75 and
above, system will display "You Passed", if not,
system will display "You Failed".
Sample Problem
2. Create a flowchart that will ask for the total
price purchased by a customer from a
department store. If the total price is Php500
and above, customer is entitled for a 30%
discount which will also be computed and
displayed on the system, otherwise "You are not
entitled for the discount" message should be
displayed.
Practice Exercise
1. A flowchart that will ask for a password of the computer. The correct
password is "Tamaraw". If the password is correct, "Welcome to Grade
10-Tamaraw" will be displayed, otherwise, "Access Denied".
2. There are only two kinds of employee in a company "Full Time" and "Part
Time". Create a flowchart that will compute for the weekly salary of an
employee.
For "Full Time" employees:
weekly salary = monthly salary / 4
For "Part Time" employees:
weekly salary = hourly rate * 25
Decision Structure
• The flowchart segment below shows how a decision structure
is expressed in C++ as an if/else statement.
YESNO
x < y?
Calculate a
as x times 2.
Calculate a
as x plus y.
if (x < y)
a = x * 2;
else
a = x + y;
Flowchart C++ Code
Decision Structure
• The flowchart segment below shows a decision structure with
only one action to perform. It is expressed as an if statement
in C++ code.
if (x < y)
a = x * 2;
Flowchart C++ Code
YESNO
x < y?
Calculate a
as x times 2.
Repetition Structure
• A repetition structure represents part of the program that
repeats. This type of structure is commonly known as a loop.
Repetition Structure
• Notice the use of the diamond symbol. A loop tests a
condition, and if the condition exists, it performs an action.
Then it tests the condition again. If the condition still exists,
the action is repeated. This continues until the condition no
longer exists.
Repetition Structure
• In the flowchart segment, the question “is x < y?” is asked. If
the answer is yes, then Process A is performed. The question
“is x < y?” is asked again. Process A is repeated as long as x is
less than y. When x is no longer less than y, the repetition
stops and the structure is exited.
x < y? Process A
YES
Repetition Structure
• The flowchart segment below shows a repetition structure
expressed in C++ as a while loop.
while (x < y)
x++;
Flowchart C++ Code
x < y? Add 1 to x
YES
Controlling a Repetition Structure
• The action performed by a repetition structure must
eventually cause the loop to terminate. Otherwise, an infinite
loop is created.
• In this flowchart segment, x is never changed. Once the loop
starts, it will never end.
• QUESTION: How can this
flowchart be modified so
it is no longer an infinite
loop?
x < y? Display x
YES
Controlling a Repetition Structure
• ANSWER: By adding an action within the repetition that
changes the value of x.
x < y? Display x Add 1 to x
YES
Sample Problem
1. A flowchart that will identify the grade
entered by the user. If the grade is 75 and
above, system will display "You Passed", if not,
system will display "You Failed".
Sample Problem
2. Create a flowchart that will ask for the total
price purchased by a customer from a
department store. If the total price is Php500
and above, customer is entitled for a 30%
discount which will also be computed and
displayed on the system, otherwise "You are not
entitled for the discount" message should be
displayed.
Practice Exercise
1. A flowchart that will ask for a password of the computer. The correct
password is "Tamaraw". If the password is correct, "Welcome to Grade
10-Tamaraw" will be displayed, otherwise, "Access Denied".
2. There are only two kinds of employee in a company "Full Time" and "Part
Time". Create a flowchart that will compute for the weekly salary of an
employee.
For "Full Time" employees:
weekly salary = monthly salary / 4
For "Part Time" employees:
weekly salary = hourly rate * 25
A Pre-Test Repetition Structure
• This type of structure is known as a pre-test repetition
structure. The condition is tested BEFORE any actions are
performed.
x < y? Display x Add 1 to x
YES
A Pre-Test Repetition Structure
• In a pre-test repetition structure, if the condition does not
exist, the loop will never begin.
x < y? Display x Add 1 to x
YES
A Post-Test Repetition Structure
• This flowchart segment shows a post-test
repetition structure.
• The condition is tested AFTER the actions
are performed.
• A post-test repetition structure always
performs its actions at least once.
Display x
Add 1 to x
YES
x < y?
A Post-Test Repetition Structure
• The flowchart segment below shows a post-test repetition
structure expressed in C++ as a do-while loop.
do
{
cout << x << endl;
x++;
} while (x < y);
Flowchart
C++ Code
Display x
Add 1 to x
YES
x < y?
Case Structure
• One of several possible actions is taken, depending
on the contents of a variable.
Case Structure
• The structure below indicates actions to perform
depending on the value in years_employed.
CASE
years_employed
1 2 3 Other
bonus = 100 bonus = 200 bonus = 400 bonus = 800
Case Structure
CASE
years_employed
1 2 3 Other
bonus = 100 bonus = 200 bonus = 400 bonus = 800
If years_employed = 1,
bonus is set to 100
If years_employed = 2,
bonus is set to 200
If years_employed = 3,
bonus is set to 400
If years_employed is
any other value, bonus
is set to 800
Connectors
• Sometimes a flowchart will not fit on one
page.
• A connector (represented by a small circle)
allows you to connect two flowchart
segments.
A
Connectors
A
ASTART
END
•The “A” connector
indicates that the second
flowchart segment begins
where the first segment
ends.
Modules
• A program module (such as a function in C++)
is represented by a special symbol.
Modules
•The position of the module
symbol indicates the point the
module is executed.
•A separate flowchart can be
constructed for the module.
START
END
Read Input.
Call calc_pay
function.
Display results.
Combining Structures
• Structures are commonly combined to create more complex
algorithms.
• The flowchart segment below combines a decision structure
with a sequence structure.
x < y? Display x Add 1 to x
YES
Combining Structures
• This flowchart segment
shows two decision
structures combined.
Display “x is
within limits.”
Display “x is
outside the limits.”
YESNO
x > min?
x < max?
YESNO
Display “x is
outside the limits.”
Review
• What do each of the following symbols
represent?
(Answer on next slide)
Answer
• What do each of the following symbols
represent?
Terminal
Input/Output
Operation
Process
Decision
Connector
Module
Review
• Name the four flowchart structures.
(Answer on next slide)
Answer
• Sequence
• Decision
• Repetition
• Case
• What type of structure is this?
Review
(Answer on next slide)
Answer
• Repetition
• What type of structure is this?
Review
(Answer on next slide)
Answer
• Sequence
• What type of structure is this?
Review
(Answer on next slide)
Answer
• Case
• What type of structure is this?
Review
(Answer on next slide)
Answer
• Decision

Grade 10 flowcharting

  • 1.
  • 2.
    What is aFlowchart? • A flowchart is a diagram that depicts the “flow” of a program. • The figure shown here is a flowchart for calculating the age. START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END
  • 3.
    Basic Flowchart Symbols •Notice there are three types of symbols in this flowchart: – rounded rectangles – parallelograms – a rectangle • Each symbol represents a different type of operation. Rounded Rectangle Parallelogram Rectangle Rounded Rectangle START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END
  • 4.
    Basic Flowchart Symbols •Terminals – represented by rounded rectangles – indicate a starting or ending point Terminal START END Terminal START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END
  • 5.
    Basic Flowchart Symbols •Input/Output Operations – represented by parallelograms – indicate an input or output operation Enter Present year Display Age Input/Output Operation START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END
  • 6.
    Basic Flowchart Symbols •Processes – represented by rectangles – indicates a process such as a mathematical computation or variable assignment Age = Present Year- Year of Birth Process START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END
  • 7.
    Stepping Through the Flowchart Enterthe present year: Variable Contents: Present Year: ? Year of Birth: ? Age: ? Output Operation Stepping Through the Flowchart START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable - a data item that may take on more than one value during the runtime of a program.
  • 8.
    Stepping Through the Flowchart Enterthe Present Year: 2016 Input Operation (User types 2016) Stepping Through the Flowchart START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable Contents: Present Year: 2016 Year of Birth: ? Age: ? Variable - a data item that may take on more than one value during the runtime of a program.
  • 9.
    Stepping Through the Flowchart Enteryour Year of birth: Output Operation Stepping Through the Flowchart START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable Contents: Present Year: 2016 Year of Birth: ? Age: ? Variable - a data item that may take on more than one value during the runtime of a program.
  • 10.
    Stepping Through the Flowchart Enteryour Year of Birth: 1990 Input Operation (User types 1990) Stepping Through the Flowchart Variable Contents: Present Year: 2016 Year of Birth: 1990 Age: ? START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable - a data item that may take on more than one value during the runtime of a program.
  • 11.
    Process: The difference of 2016and 1990 is 26 which is stored as Age Stepping Through the Flowchart START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable Contents: Present Year: 2016 Year of Birth: 1990 Age: 26 Enter your Year of Birth: 1990 Variable - a data item that may take on more than one value during the runtime of a program.
  • 12.
    Stepping Through the Flowchart Ageis 26 Output Operation START Display message “Enter the present year” Read Present year Display message “Enter your year of birth” Read Year of birth Age = Present year – Year of birth Display Age END Variable Contents: Present Year: 2016 Year of Birth: 1990 Age: 26 Variable - a data item that may take on more than one value during the runtime of a program.
  • 13.
    Sample Problems: 1. Createa flowchart that will get the sum of two integers. 2. Create a flowchart that will convert a peso to dollar. Exchange rate is $. 1.00 = Php. 45.00 (fixed)
  • 14.
    Exercise Problems: 1. Createa flowchart that will convert a Celsius value to Fahrenheit. F= C * 9/5 +32 2. Create a flowchart that will get the Average of three integers.
  • 15.
    Four Flowchart Structures •Sequence • Decision • Repetition • Case
  • 16.
    Sequence Structure • aseries of actions are performed in sequence • The pay-calculating example was a sequence flowchart.
  • 17.
    Decision Structure • Oneof two possible actions is taken, depending on a condition.
  • 18.
    Decision Structure • Anew symbol, the diamond, indicates a yes/no question. If the answer to the question is yes, the flow follows one path. If the answer is no, the flow follows another path YESNO
  • 19.
    Decision Structure • Inthe flowchart segment below, the question “is x < y?” is asked. If the answer is no, then process A is performed. If the answer is yes, then process B is performed. YESNO Is x < y? Process BProcess A
  • 20.
    Sample Problem 1. Aflowchart that will identify the grade entered by the user. If the grade is 75 and above, system will display "You Passed", if not, system will display "You Failed".
  • 21.
    Sample Problem 2. Createa flowchart that will ask for the total price purchased by a customer from a department store. If the total price is Php500 and above, customer is entitled for a 30% discount which will also be computed and displayed on the system, otherwise "You are not entitled for the discount" message should be displayed.
  • 22.
    Practice Exercise 1. Aflowchart that will ask for a password of the computer. The correct password is "Tamaraw". If the password is correct, "Welcome to Grade 10-Tamaraw" will be displayed, otherwise, "Access Denied". 2. There are only two kinds of employee in a company "Full Time" and "Part Time". Create a flowchart that will compute for the weekly salary of an employee. For "Full Time" employees: weekly salary = monthly salary / 4 For "Part Time" employees: weekly salary = hourly rate * 25
  • 23.
    Decision Structure • Theflowchart segment below shows how a decision structure is expressed in C++ as an if/else statement. YESNO x < y? Calculate a as x times 2. Calculate a as x plus y. if (x < y) a = x * 2; else a = x + y; Flowchart C++ Code
  • 24.
    Decision Structure • Theflowchart segment below shows a decision structure with only one action to perform. It is expressed as an if statement in C++ code. if (x < y) a = x * 2; Flowchart C++ Code YESNO x < y? Calculate a as x times 2.
  • 25.
    Repetition Structure • Arepetition structure represents part of the program that repeats. This type of structure is commonly known as a loop.
  • 26.
    Repetition Structure • Noticethe use of the diamond symbol. A loop tests a condition, and if the condition exists, it performs an action. Then it tests the condition again. If the condition still exists, the action is repeated. This continues until the condition no longer exists.
  • 27.
    Repetition Structure • Inthe flowchart segment, the question “is x < y?” is asked. If the answer is yes, then Process A is performed. The question “is x < y?” is asked again. Process A is repeated as long as x is less than y. When x is no longer less than y, the repetition stops and the structure is exited. x < y? Process A YES
  • 28.
    Repetition Structure • Theflowchart segment below shows a repetition structure expressed in C++ as a while loop. while (x < y) x++; Flowchart C++ Code x < y? Add 1 to x YES
  • 29.
    Controlling a RepetitionStructure • The action performed by a repetition structure must eventually cause the loop to terminate. Otherwise, an infinite loop is created. • In this flowchart segment, x is never changed. Once the loop starts, it will never end. • QUESTION: How can this flowchart be modified so it is no longer an infinite loop? x < y? Display x YES
  • 30.
    Controlling a RepetitionStructure • ANSWER: By adding an action within the repetition that changes the value of x. x < y? Display x Add 1 to x YES
  • 31.
    Sample Problem 1. Aflowchart that will identify the grade entered by the user. If the grade is 75 and above, system will display "You Passed", if not, system will display "You Failed".
  • 32.
    Sample Problem 2. Createa flowchart that will ask for the total price purchased by a customer from a department store. If the total price is Php500 and above, customer is entitled for a 30% discount which will also be computed and displayed on the system, otherwise "You are not entitled for the discount" message should be displayed.
  • 33.
    Practice Exercise 1. Aflowchart that will ask for a password of the computer. The correct password is "Tamaraw". If the password is correct, "Welcome to Grade 10-Tamaraw" will be displayed, otherwise, "Access Denied". 2. There are only two kinds of employee in a company "Full Time" and "Part Time". Create a flowchart that will compute for the weekly salary of an employee. For "Full Time" employees: weekly salary = monthly salary / 4 For "Part Time" employees: weekly salary = hourly rate * 25
  • 34.
    A Pre-Test RepetitionStructure • This type of structure is known as a pre-test repetition structure. The condition is tested BEFORE any actions are performed. x < y? Display x Add 1 to x YES
  • 35.
    A Pre-Test RepetitionStructure • In a pre-test repetition structure, if the condition does not exist, the loop will never begin. x < y? Display x Add 1 to x YES
  • 36.
    A Post-Test RepetitionStructure • This flowchart segment shows a post-test repetition structure. • The condition is tested AFTER the actions are performed. • A post-test repetition structure always performs its actions at least once. Display x Add 1 to x YES x < y?
  • 37.
    A Post-Test RepetitionStructure • The flowchart segment below shows a post-test repetition structure expressed in C++ as a do-while loop. do { cout << x << endl; x++; } while (x < y); Flowchart C++ Code Display x Add 1 to x YES x < y?
  • 38.
    Case Structure • Oneof several possible actions is taken, depending on the contents of a variable.
  • 39.
    Case Structure • Thestructure below indicates actions to perform depending on the value in years_employed. CASE years_employed 1 2 3 Other bonus = 100 bonus = 200 bonus = 400 bonus = 800
  • 40.
    Case Structure CASE years_employed 1 23 Other bonus = 100 bonus = 200 bonus = 400 bonus = 800 If years_employed = 1, bonus is set to 100 If years_employed = 2, bonus is set to 200 If years_employed = 3, bonus is set to 400 If years_employed is any other value, bonus is set to 800
  • 41.
    Connectors • Sometimes aflowchart will not fit on one page. • A connector (represented by a small circle) allows you to connect two flowchart segments. A
  • 42.
    Connectors A ASTART END •The “A” connector indicatesthat the second flowchart segment begins where the first segment ends.
  • 43.
    Modules • A programmodule (such as a function in C++) is represented by a special symbol.
  • 44.
    Modules •The position ofthe module symbol indicates the point the module is executed. •A separate flowchart can be constructed for the module. START END Read Input. Call calc_pay function. Display results.
  • 45.
    Combining Structures • Structuresare commonly combined to create more complex algorithms. • The flowchart segment below combines a decision structure with a sequence structure. x < y? Display x Add 1 to x YES
  • 46.
    Combining Structures • Thisflowchart segment shows two decision structures combined. Display “x is within limits.” Display “x is outside the limits.” YESNO x > min? x < max? YESNO Display “x is outside the limits.”
  • 47.
    Review • What doeach of the following symbols represent? (Answer on next slide)
  • 48.
    Answer • What doeach of the following symbols represent? Terminal Input/Output Operation Process Decision Connector Module
  • 49.
    Review • Name thefour flowchart structures. (Answer on next slide)
  • 50.
  • 51.
    • What typeof structure is this? Review (Answer on next slide)
  • 52.
  • 53.
    • What typeof structure is this? Review (Answer on next slide)
  • 54.
  • 55.
    • What typeof structure is this? Review (Answer on next slide)
  • 56.
  • 57.
    • What typeof structure is this? Review (Answer on next slide)
  • 58.