COMPUTER STUDIES SSS2

MODEL SECONDARY SCHOOL MAITAMA

(FCT SEC EDU BOARD)

SUBJECT: COMPUTER STUDIES

NAME: OKUNNUSI FELIX

CLASS: SS2 (3rd term 2020)

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WEEK 1

ALGORITHMS AND FLOWCHART

FLOWCHART SYMBOLS
DEFINITION OF ALGORITHM:
It is simply a sequence of clear, precise and unambiguous instructions for solving a problem or
task in determined and finite number of steps of operation.
DESCRIPTION OF FLOWCHART: It is a type of a diagram that represents an algorithm,
workflow or process, showing the steps as boxes of various kinds and their order by
connecting them with arrows aimed at illustrating a solution to a given problem.
TYPES OF FLOWCHART:
i. System
ii. Program
iii. Block
iv. Procedure flowchart.
Flowchart symbols

i. Terminal: the beginning, end or a point of interruption in a

program.

ii. Connector: an entry from or an exit to another of the program

flowchart.

iii. Processing: a group of program instructions which perform a

processing function in the program.

iv. Decision: used to document points where a branch to

alternative paths possible based upon variable conditions.

v. Manual input: any function of an input/ output device

vi. Display: it displays information.

Practice Questions:
Define Algorithm.
Describe a flow chart.
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State the types of flowchart available.

Draw flow chart symbols.
ASSIGNMENT: draw and name 5 flowchart symbols.

LESSON TOPIC: FUNCTIONS OF ALGORITHM/FLOWCHART

1. I t is a deterministic automation for accomplishing a goal.

2. It is capable of fusing basic operations e. g multiply-add operations.
3. Provides architectural hardware for building operations.
4. It is used to define an abstract computational complexity theory.
5. It acts as the skeleton behind programming languages for easier interpretations.

Practice Questions

1. Identify flowchart symbols

2. Draw flow charts symbols without the instructional resources
3. State the functions of algorithm and flowchart.
4. Mention some practical applications of Algorithms and flowcharts

LESSON TOPIC: CHARACTERISTICS OF ALGORITHM

Not all procedures can be called an algorithm. An algorithm should have the following
characteristics
1. Unambiguous − Algorithm should be clear and unambiguous. Each of its steps (or
phases), and their inputs/outputs should be clear and must lead to only one meaning.
2. Input − An algorithm should have 0 or more well-defined inputs.
3. Output − An algorithm should have 1 or more well-defined outputs, and should match
the desired output.
4. Finiteness − Algorithms must terminate after a finite number of steps.
5. Feasibility − Should be feasible with the available resources.
6. Independent − An algorithm should have step-by-step directions, which should be
independent of any programming code.
7. Precision – the steps are precisely stated(defined).
8. Uniqueness – results of each step are uniquely defined and only depend on the input
and the result of the preceding steps.
9. Generality – the algorithm applies to a set of inputs.
Practice Questions:

1. List 8 characteristics of an algorithm.

2. Describe the uniqueness of an algorithm.
3. Explain unambiguity as a characteristic of algorithm.
4. Give the role of finiteness as a characteristic of an algorithm.

ASSIGNMENT: write an algorithm showing all the characteristics of an algorithm.

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LESSON TOPIC: FUNCTIONS OF ALGORITHM

WRITING ALGORITHM FOR COMPUTATION/FLOWCHART

Example: An Algorithm to compute an average of a given set of numbers.
Given scores 3,5,7,9,11 Where A=Average.

L
E

WRITING AN ALGORITHM FOR EQUATION EVALUATION

Example: evaluation of equation: y=a (b-c)2/d+2

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WRITING AN ALGORITHM FOR PRINTING NUMBERS.

Example: an algorithm to print the first ten odd numbers.

YES NO

Practice Questions:

1. State the functions of algorithms.

2. Describe an algorithm for computation/flowchart
3. Enumerate an algorithm for equation evaluation/flowchart.
4. Write an algorithm for printing numbers/flowchart.

ASSIGNMENT: Write an algorithm illustrated on a flowchart to calculate the Area A of a

rectangle with base B and height H.

LESSON TOPIC: ADVANTAGES AND DISADVANTAGES OF FLOWCHART SYMBOLS OR

DIAGRAMS.

SUB-TOPIC: USING FLOWCHART DIAGRAMMS FOR SOLVING GIVEN PROBLEMS

ADVANTAGES OF FLOWCHART SYMBOL:

1. They are easy to flow

2. They can be produced in a standard way and also allow several people to work on them
simultaneously.
3. They are useful to the systems analyst for experimenting with different approaches to a
particular problem.
4. They show logical interrelationship clearly.
5. They allow tracing of actions, which depend on conditions.

DISADVANTAGES OF FLOWCHART SYMBOLS.

1) Flowcharting can be very time consuming especially on larger complex programs.

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2) Owing to the symbol-string of flowcharting, any changes or modifications in the program

logic will usually require a completely new flowchart.
3) Procedures represented by flowchart may not be easy for a lay man to understand.

FLOWCHART DIAGRAMS TO REPLY A LETTER FROM A FRIEND

READ FRIEND’S LETTER

DECIDE WHAT TO WRITE

WRITE LETTER IN REPLY

FLOWCHART DIAGRAMS TO CALCULATE THE AREA A OF A TRIANGLE WITH BASE B AND

HEIGHT H

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FLOWCHART DIAGRAMS TO ASSIGN 2 TO A IF A>B OR ASSIGN 6 TO A IF OTHERWISE.

FLOWCHART DIAGRAMS FOR AN ALGORITHM TO COMPUTE THE AVERAGE OF 3 NUMBERS

a,b,c.

Practice Questions:

i. Mention the advantages and disadvantages of flowchart.

ii. Draw flowchart diagrams to reply a letter from a friend.
iii. Describe a flowchart diagram to show the calculation of the area A of a triangle with base B
and height H algorithm to compute the average of 3 numbers a,b,c..

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iv. Draw flowchart diagrams to assign 2 to A if A>B or assign 6 to A if otherwise and for an
C.ASSIGNMENT:
Write an algorithm illustrated on a flowchart to calculate the Area A of a rectangle with base B
and height H.
State 5 uses of the DECISION flow chart symbol by way of practical application.

WEEK 4 (1stContact)

UNIT TOPIC: BASIC PROGRAMMING

LESSON TOPIC: BUILT-IN FUNCTIONS

INTRODUCING BASIC-DEFINITION:

The word BASIC means Beginners All Purpose Symbolic Instruction Code and it is a
programming language that is easy to learn and used to perform mathematical calculations and
also to draw images.

BASIC TERMINOLOGIES

1. Lines: a program consists of lines of texts so that the order of the lines in the program is the
order in which they are read by the computer.
2. Keywords: the lines contain statements which tell the computer what to do, these statements
are called keywords e.g REM, PRINT, INPUT, LET, END, STOP.
3. Constants: they are written in the usual way with or without a decimal point and with or
without a minus sign. e.g 7,-54,3.1428, -0.0011 etc.
N/B: Numerical constants may be written with a scale factor which is a power of 10 while
symbolic constants are those with a name defined by the keyword constant.
4. Variables: it is the name of a location in the computer memory where a number or a string is
stored. e.g x,y

DESCRIPTION OF BUILT-IN FUNCTIONS: Built-in functions are BASIC programming functions

that are already made available in BASIC to carry out any operation when required and to call
in a built-in function, the name of the function is written followed by the arguments in
parentheses e.g ‘Tan2(y+z,)’

EXAMPLES OF BUILT-IN FUNCTIONS AND THEIR FUNCTIONS

 SQR(X): This gives you the positive square root of x and reports if x is negative.e.g SQR(4)=2.
 -INT(X): This produces the nearest integer to x located between x and zero truncated toward
zero e.g int(3)=3,int(3.9)=3, int (-3.9)=-3,and int-(3)=-3 as well.
 SIN(X): This gives you the sin of x with x in radians.
 RND(X): this gives you a random number whose values are usually uniformly distributed
between zero and one but the value is never zero and never one.
 COS(X):This gives you the cosine of x with x in radians.
 TAN (X): This gives you the cosine of x with x in radians.
 LOG(X): This gives you the natural logarithms o x if x is positive, otherwise it reports an error.
 EXP(X):This gives the exponential of x (e^x), or reports an error if x is out of range .The range
of values x can have depends on your machine’s floating point o representation.
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Practice Questions:

i. Define BASIC Programming language.

ii. List and explain some BASIC terminologies.
iii. Describe Built-in functions.
iv. Identify and state the functions of some built-in functions e.g COS(X), TAN(X),LOG(X)
C.ASSIGNMENT: Identify and state the functions of SQR,INT(X),SIN (X),ABS(X), and RND(X) as
built-in functions.

WEEK 4(2nd Contact)

LESSON TOPIC: BASIC NOTATIONS

Xamples of BASIC notations

BASIC notation of √b2-4ac/2a is √b^2-4*a*c/2*a.

(x-y)(x+y) in BASIC notation is becomes (x-y)*(x+y)

(a+b) +c/sin d. becomes (a+b)*1+c/sin d

(ex-y)-sin(x+ny) is given as (ex-y)-sin(x+ny)

and b=1/4ac is represented as b=1/4*a*c

Practice Questions

i. Write the BASIC notation of √b2-4ac/2a.

ii. Demonstrate the conversion of (x-y)(x+y) to a BASIC notation.

iii. State the BASIC notation of (a+b)+c/sin d.

iv. Show the BASIC notation of (ex-y)-sin(x+ny) and b=1/4ac

ASSIGNMENT: Write the BASIC notation of the following:

i. a=(-b+d)/2c
ii. z=x/y+c
iii. c-9c/5+32

WEEK 5(1stContact)
LESSON TOPIC: BASIC PROGRAMS TO SOLVE MATHEMATICAL PROBLEMS
FINDING THE SQUARE ROOT OF NUMBERS WITHIN A GIVEN RANGE.
e.g (1,15)
print x, 1+10**-x……………….1
FINDING THE SQUARE ROOT UP TO AN INTEGER.
Def sqrt 1(num):
If num<0
Raise value Error
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If num==1:
Return 1
For k in range (1+(num/2)):
If k **2=num:
Return k-1
Return k.
FINDING THE SQUARE ROOT OF KNOWN VALUES.
e.g 9
number=9, estimate=(9+1)/2.0=5.0
new estimate=(5+9/5))/2.0=3.4 which is closer to the answer
FINDING THE TANGENT OF A GIVEN ANGLE.
Input angle 30
Read degrees ( 0 )
Enter tan value
Output Degrees ( 0 )………30π/6: 0.5773
Practice Questions
i. Find the square root of numbers within a given range.
ii. Enumerate the square root up to an integer.
iii. Evaluate the square root of known values.
iv. Find the tangent of a given angle.
C.ASSIGNMENT: Write the BASIC program to compute the square root of numbers from 50 to
100.
WEEK 5 (2nd Contact)
LESSON TOPIC: BASIC PROGRAMS TO SOLVE MATHEMATICAL PROBLEMS
FINDING THE SQUARE ROOT OF A POSITIVE NUMBER

10 PRINT SQR (165)

THE ABSOLUTE VALUE OF A GIVEN NUMBER

10 CLS
20 LET A = 10
30 LET B = 12
40 LET C = A+B
50 PRINT ABS (C )
60 END

EVALUATING LOG, SIN, COS AND TANGENTS OF ANGLES AND PLOT THE SIN AND COSINE
GRAPHS.

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LOG- Using natural logarithm

10 CLS
20 PRINT LOG (36.2)
SIN- Finds the Sine of an angle.
10 CLS
20 CONST PI3.141592654
30 PRINT (SIN (90*(PI/180)))
40 END
COS- Finds the Cosine of an angle
10 CLS
20 CONST PI = 3.141592654
30 PRINT (COS (10*(P1/180)))
40 END
TAN- Finds the Tangent of an angle
10 PRINT TAN (54)

PLOT SINE WAVE CURVE (SIN X)

Y=SIN(X)

Y=sin (x) OSCILLATING

y-2sin2(x-1/4) the interval (0,2)
N/B x=a range (0,2,0,01)y=*sin
(2*pi*(x-1/4))plot (x,y)
X label (‘x-axis’)
Y label (‘y-axis’)
Title(r’$y=2/sin)
Show( )

PLOT COSINE CURVE (COS X)

Y=COS(X)
y-2cos2(x-1/4) the interval (0,2)
N/B x=a range (0,2,0,01)y=*cos
(2*pi*(x-1/4))plot (x,y)
X label (‘x-axis’)
Y label (‘y-axis’)
Title(r’$y=2/cos)
Show( )
Hence the difference between the sine and cosine curves is just that the cosine curve is shifted
900 to the left.

FIND THE EXPONENT AND THE INTEGER OF A REAL NUMBER.

EXP- Finds the exponent of a number
10 CLS

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20 PRINT EXP (6)

30 END
INT- Find the integer of a real number
10 CLS
20 PRINT INT (3544.6)
30 END
Practice Questions:
i. Find the square root of a positive number using SQR ( )
ii. Enumerate the absolute value of a given number using ABS ( )
iii. Evaluate the Log, Sin, Cos and Tangents of angles and Plot the Sin and Cosine graphs.
iv. Find the exponent and the integer of a real number
C.ASSIGNMENT: State the difference between the sine wave curve and the cosine wave curve.

WEEK 6 (2nd Contact)

LESSON TOPIC: INTERNET

DEFINITION OF TERMS
DEFINITION OF THE INTERNET: The internet as a global connection of computers via a huge
network of telecommunication links.

INTRANET is a computer network that uses Internet Protocol technology to share information,
operational systems or computing services within an organization unlike internet which is a
network between organizations while INTERNET is a global connection of computers through
a wide network of communication links.

DEFINITION OF TERMS

1. A BROWSER: A software application used to locate and display web pages e.g. Netscape
Navigator, MS Internet Explorer, Opera, Mozilla Firefox, Spyglass Mosaic etc.
2. A CHART-ROOM: A center for chatting with loved ones, business associates etc. online.
3. A CYBER CAFÉ: A computer center with dedicated internet connection.
4. DOWNLOAD: To retrieve information from a dedicated server online.
5. THE E-MAIL: It is an acronym for electronic mail which is a letter composed and sent or
received via computer or other electronic means.
6. HOMEPAGE: A home page is a page on the World wide Web which contains links to other
documents and resources throughout the internet. Hence it is a web page which is displayed
each time the internet explorer or a web browser is launched.
7. HTML: it refers to as HYPERTEXT MARK UP LANGUAGE. It is the basic programming language
of the world wide web based upon SGML (STANDARD GENERALIZED MARKUP LANGUAGE)
8. HTTP: HYPERTEXT TRANSFER PROTOCOL: An application protocol for distributed,
collaborative, hypermedia information.
9. URL: UNIFORM RESOURCE LOCATOR. The address to any web site or web page document that
is a part of the World Wide Web.

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10. HYPERLINK: words, text image or an object in a web page document or that connect or links
other documents online.

USES OF THE INTERNET

1. To send and receive mails in a matter of seconds.
2. To apply for scholarship or carry out research on any topic.
3. To download free software or advertise your business.
4. To get the latest news or purchase products from around the world.
5. To preview music and video clips or make travel reservations.
6. To apply for employment opportunities.
7. To study and obtain certificates.
8. To chat with loved ones beyond immediate locations.

Practice Questions:
i. Define the term “INTERNET”
ii. Differentiate between INTERNET and INTRANET
ii. Define the common related terms to the concept of the internet.
iv. State five uses of the internet.
ASSIGNMENT: State the difference between the sine wave curve and the cosine wave curve.

WEEK 8(2nd Contact)

WEEK 9 (2nd Contact)

UNIT TOPIC: INTERNET SERVICES

LESSON TOPIC: THE ELECTRONIC MAIL
FEATURES IN MAIN BROWSER WINDOW

1) The title bar.

2) The menu bar.
3) The tool bar.
4) The address bar.

INTERNET SERVICES

i. E-mail: electronic mail

ii. E-mail discussion group: discussion groups formed online via electronic messages.
iii. Telnet: TERMINAL EMULATION PROTOCOL which allows users to log in to host computers
remotely over the internet.
iv. Usenet: A distributed world-wide system of topical discussion groups which are arranged
according to abbreviated prefix and suffix groups. e.g. alt: prefix indicating alternative
discussion groups, comp: for computer related discussion groups, rec: meaning recreational
discussion groups.
v. Veronica: VERY EASY RODENT ORIENTED NET WIDE INDEX COMPUTERIZED ARCHIVES: A
search engine which locates menu items from Gopher servers all around the world.
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ELECTRONIC MAIL (E-MAIL SERVICES): the service is referred to as mail and a single piece of
electronic mail is called a message while e-mail services include the following:
a. sending e-mail
b. receiving e-mail
c. charting
d. creating e-mail account
e. opening mail boxes
f. Check directories
g. Shared calendars and public folders

STEPS INVOLVED IN CREATING AN E-MAIL ACCOUNT:

1. Visit a website that offers an email service e.g yahoo.com, google.com, hotmail.com etc.
2. Find where to sign up.
3. Follow all the instructions on the page, filling out all the needed details.
4. Read over the service agreement and click the box saying you agree to abide by the email
system rules.
5. Click on the submit or ok or enter button.

Practice Questions:
i. Identify the features in main browser window.
ii. list at least 5 internet services available.
ii. Enumerate 5 most common e-mail services.
iv. State the steps involved in creating an e-mail account.
ASSIGNMENT: send an e-mail to your teacher telling her of the efforts you are making to
prepare or your promotion exams.
WEEK 10(2nd Contact)

UNIT TOPIC: INTERNET SERVICES

LESSON TOPIC: THE ELECTRONIC MAIL
STEPS INVOLVED IN OPENING A MAIL BOX:

1. go to e-mail address

2. locate box

3. click open

FEATURES IN AN E-MAIL ADDRESS

e.g finemail@finegovng.org
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finemail = local part (name of a mail box or user name)

@= symbol (separator)
Finegovng.org (domain name)
WEBSITE ADDRESS FEATURES
Example 1 www.finegovng.org
Example 2 http://www.cnn.com
Example 3 https://www.cnn.com

http://= hypertext transfer protocol (helps web browser locate web page or site and display it)
www= World Wide Web (means the page you are looking for is on the web)
cnn= name of server or web site
.com= the domain (where the webpage is registered and what kind of web site it is)
Examples of domains:
.com = commercial site
.gov = government site
. org = organization site
.edu= educational institution site

DEFINITION OF CHATTING AND STEPS INVOLVED IN CHATTING

Chatting is making petty conversation online.

Steps involved in chatting:

1. See whether your friend is online (this is indicated by a green dot, yellow if they are busy and
red if offline or invisible)
2. Click on their name on the chat list. (Sometimes it’s hidden but you can find it on any box
named ‘chat’ on your layout).
3. Type in anything and go ahead making conversation.

Practice Questions:
i. Identify the steps in opening a mail box
ii. Mention observable features in an e-mail address
ii. State website addresses and features
iv. Define chatting and state the steps involved in chatting.
ASSIGNMENT: practically chat with a group member online.

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