Textbook: Revision of Level I | Computer Science for Class 2 PDF Download

 Page 1


m A
i
In this lesson you will:
Revise the topics learnt in the previous level.
Moz walks in and sees that Jyoti is wiping the monitor with a soft 
duster while Tejas is wiping the CPU. 
Uses of a Computer
A computer can be used for many simple tasks like: 
   Drawing pictures                        Adding numbers
   Writing letters                          Watching movies and cartoons
   Playing games                             Listening to music 
Parts of a Computer
Tejas writes about the CPU and the mouse. Jyoti writes about the 
monitor and the keyboard. 
CPU
CPU (Central Processing Unit) is the most 
important part of a computer. It does all the 
tasks that we want the computer to do. 
Lesson1
Revision of Level I
Moz: Hello children. Let me help you in keeping the 
computers clean. I will also check the connections. 
Meanwhile, you write about the uses and parts of a 
computer. I have kept some sheets of paper on the desk. 
Page 2


m A
i
In this lesson you will:
Revise the topics learnt in the previous level.
Moz walks in and sees that Jyoti is wiping the monitor with a soft 
duster while Tejas is wiping the CPU. 
Uses of a Computer
A computer can be used for many simple tasks like: 
   Drawing pictures                        Adding numbers
   Writing letters                          Watching movies and cartoons
   Playing games                             Listening to music 
Parts of a Computer
Tejas writes about the CPU and the mouse. Jyoti writes about the 
monitor and the keyboard. 
CPU
CPU (Central Processing Unit) is the most 
important part of a computer. It does all the 
tasks that we want the computer to do. 
Lesson1
Revision of Level I
Moz: Hello children. Let me help you in keeping the 
computers clean. I will also check the connections. 
Meanwhile, you write about the uses and parts of a 
computer. I have kept some sheets of paper on the desk. 
Keyboard
A keyboard is used to write on the computer. We can 
also use a keyboard to give instructions to the 
computer. The buttons on the keyboard are called 
‘keys?.  The keys on which we see:
 alphabets A – Z, are called alphabet keys.
        numbers 0 – 9, are called number keys.
                keys with words like Enter, Backspace are called 
                special keys. 
While typing, use the:
 Space bar - to leave some space between alphabets or numbers. 
   This is usually the longest key in the bottom row and has nothing  
    written  on it.
 Backspace key - to erase. This is usually the last key in the number 
    row.
 Enter key - to move to the next line. This is found at the
   end of the middle row of alphabets.
Monitor
A monitor looks like a television screen. The CPU uses 
the monitor to show us photos, movies, games, and 
other activities. The mouse pointer can be seen on 
the monitor. Often, whatever we type using the 
keyboard, can be seen on the monitor.
Mouse
A mouse is used to select an item shown on the 
monitor. The mouse usually has two buttons and a small 
wheel between the buttons. 
   To select an item, we first point to the item and 
   then click the left button. 
   To start an activity, we double click the left button. 
   To control an activity, we click the right button. 
   To move up and down a page, we use the wheel or scroll button.
It controls all the other parts, such as 
the Monitor, Keyboard and Mouse. 
These parts have to be connected to 
the CPU, for them to work.
Page 3


m A
i
In this lesson you will:
Revise the topics learnt in the previous level.
Moz walks in and sees that Jyoti is wiping the monitor with a soft 
duster while Tejas is wiping the CPU. 
Uses of a Computer
A computer can be used for many simple tasks like: 
   Drawing pictures                        Adding numbers
   Writing letters                          Watching movies and cartoons
   Playing games                             Listening to music 
Parts of a Computer
Tejas writes about the CPU and the mouse. Jyoti writes about the 
monitor and the keyboard. 
CPU
CPU (Central Processing Unit) is the most 
important part of a computer. It does all the 
tasks that we want the computer to do. 
Lesson1
Revision of Level I
Moz: Hello children. Let me help you in keeping the 
computers clean. I will also check the connections. 
Meanwhile, you write about the uses and parts of a 
computer. I have kept some sheets of paper on the desk. 
Keyboard
A keyboard is used to write on the computer. We can 
also use a keyboard to give instructions to the 
computer. The buttons on the keyboard are called 
‘keys?.  The keys on which we see:
 alphabets A – Z, are called alphabet keys.
        numbers 0 – 9, are called number keys.
                keys with words like Enter, Backspace are called 
                special keys. 
While typing, use the:
 Space bar - to leave some space between alphabets or numbers. 
   This is usually the longest key in the bottom row and has nothing  
    written  on it.
 Backspace key - to erase. This is usually the last key in the number 
    row.
 Enter key - to move to the next line. This is found at the
   end of the middle row of alphabets.
Monitor
A monitor looks like a television screen. The CPU uses 
the monitor to show us photos, movies, games, and 
other activities. The mouse pointer can be seen on 
the monitor. Often, whatever we type using the 
keyboard, can be seen on the monitor.
Mouse
A mouse is used to select an item shown on the 
monitor. The mouse usually has two buttons and a small 
wheel between the buttons. 
   To select an item, we first point to the item and 
   then click the left button. 
   To start an activity, we double click the left button. 
   To control an activity, we click the right button. 
   To move up and down a page, we use the wheel or scroll button.
It controls all the other parts, such as 
the Monitor, Keyboard and Mouse. 
These parts have to be connected to 
the CPU, for them to work.
Paint activity
Tejas double clicks on the paint icon. The paint activity 
window opens. 
Tejas first opens an existing file and plays with the colours. 
Then he creates his own painting. He knows that:
    The tools for drawing can be found under Tools.
    A set of tools is called a Toolbar.
    The various choices in any Toolbar are called the Options.
The tools and options that Tejas uses to draw a house are:
    New option to get a blank canvas.
    Shapes toolbar to get shapes like square, rectangle and triangle.
    Brushes toolbar to colour using the colour palette.
    Eraser to erase.
    Save option to save the painting.
    Print option to print the painting.
    Quit option to quit the activity.
Tejas: We have finished. Now can I paint using the computer? 
Jyoti: I want to listen to music.
Moz: Ok. Go ahead. You know how to start an activity.
 
 
Page 4


m A
i
In this lesson you will:
Revise the topics learnt in the previous level.
Moz walks in and sees that Jyoti is wiping the monitor with a soft 
duster while Tejas is wiping the CPU. 
Uses of a Computer
A computer can be used for many simple tasks like: 
   Drawing pictures                        Adding numbers
   Writing letters                          Watching movies and cartoons
   Playing games                             Listening to music 
Parts of a Computer
Tejas writes about the CPU and the mouse. Jyoti writes about the 
monitor and the keyboard. 
CPU
CPU (Central Processing Unit) is the most 
important part of a computer. It does all the 
tasks that we want the computer to do. 
Lesson1
Revision of Level I
Moz: Hello children. Let me help you in keeping the 
computers clean. I will also check the connections. 
Meanwhile, you write about the uses and parts of a 
computer. I have kept some sheets of paper on the desk. 
Keyboard
A keyboard is used to write on the computer. We can 
also use a keyboard to give instructions to the 
computer. The buttons on the keyboard are called 
‘keys?.  The keys on which we see:
 alphabets A – Z, are called alphabet keys.
        numbers 0 – 9, are called number keys.
                keys with words like Enter, Backspace are called 
                special keys. 
While typing, use the:
 Space bar - to leave some space between alphabets or numbers. 
   This is usually the longest key in the bottom row and has nothing  
    written  on it.
 Backspace key - to erase. This is usually the last key in the number 
    row.
 Enter key - to move to the next line. This is found at the
   end of the middle row of alphabets.
Monitor
A monitor looks like a television screen. The CPU uses 
the monitor to show us photos, movies, games, and 
other activities. The mouse pointer can be seen on 
the monitor. Often, whatever we type using the 
keyboard, can be seen on the monitor.
Mouse
A mouse is used to select an item shown on the 
monitor. The mouse usually has two buttons and a small 
wheel between the buttons. 
   To select an item, we first point to the item and 
   then click the left button. 
   To start an activity, we double click the left button. 
   To control an activity, we click the right button. 
   To move up and down a page, we use the wheel or scroll button.
It controls all the other parts, such as 
the Monitor, Keyboard and Mouse. 
These parts have to be connected to 
the CPU, for them to work.
Paint activity
Tejas double clicks on the paint icon. The paint activity 
window opens. 
Tejas first opens an existing file and plays with the colours. 
Then he creates his own painting. He knows that:
    The tools for drawing can be found under Tools.
    A set of tools is called a Toolbar.
    The various choices in any Toolbar are called the Options.
The tools and options that Tejas uses to draw a house are:
    New option to get a blank canvas.
    Shapes toolbar to get shapes like square, rectangle and triangle.
    Brushes toolbar to colour using the colour palette.
    Eraser to erase.
    Save option to save the painting.
    Print option to print the painting.
    Quit option to quit the activity.
Tejas: We have finished. Now can I paint using the computer? 
Jyoti: I want to listen to music.
Moz: Ok. Go ahead. You know how to start an activity.
 
 
The children spend their free period in the computer room. Tejas 
saves the painting and Jyoti sings the song that she has learnt.
This is what she clicks:
    Open option to select the song that she likes.
    Play to play the song.
    Pause to stop the song and practice that line. 
    Pause or Play again to continue the song from where it had 
stopped.
    Rewind and Forward to jump to a different part of the song.
    Mute to turn off the volume.
    Slider to change the volume.
    Stop to stop the song completely.
Moz: Very good. The song is melodious. The painting is very colourful.
Using a Music Player 
Jyoti double clicks on the music file. She knows that she 
can control the music player by moving the mouse pointer 
over the control buttons.
Jana Gana Mana.mp3
Page 5


m A
i
In this lesson you will:
Revise the topics learnt in the previous level.
Moz walks in and sees that Jyoti is wiping the monitor with a soft 
duster while Tejas is wiping the CPU. 
Uses of a Computer
A computer can be used for many simple tasks like: 
   Drawing pictures                        Adding numbers
   Writing letters                          Watching movies and cartoons
   Playing games                             Listening to music 
Parts of a Computer
Tejas writes about the CPU and the mouse. Jyoti writes about the 
monitor and the keyboard. 
CPU
CPU (Central Processing Unit) is the most 
important part of a computer. It does all the 
tasks that we want the computer to do. 
Lesson1
Revision of Level I
Moz: Hello children. Let me help you in keeping the 
computers clean. I will also check the connections. 
Meanwhile, you write about the uses and parts of a 
computer. I have kept some sheets of paper on the desk. 
Keyboard
A keyboard is used to write on the computer. We can 
also use a keyboard to give instructions to the 
computer. The buttons on the keyboard are called 
‘keys?.  The keys on which we see:
 alphabets A – Z, are called alphabet keys.
        numbers 0 – 9, are called number keys.
                keys with words like Enter, Backspace are called 
                special keys. 
While typing, use the:
 Space bar - to leave some space between alphabets or numbers. 
   This is usually the longest key in the bottom row and has nothing  
    written  on it.
 Backspace key - to erase. This is usually the last key in the number 
    row.
 Enter key - to move to the next line. This is found at the
   end of the middle row of alphabets.
Monitor
A monitor looks like a television screen. The CPU uses 
the monitor to show us photos, movies, games, and 
other activities. The mouse pointer can be seen on 
the monitor. Often, whatever we type using the 
keyboard, can be seen on the monitor.
Mouse
A mouse is used to select an item shown on the 
monitor. The mouse usually has two buttons and a small 
wheel between the buttons. 
   To select an item, we first point to the item and 
   then click the left button. 
   To start an activity, we double click the left button. 
   To control an activity, we click the right button. 
   To move up and down a page, we use the wheel or scroll button.
It controls all the other parts, such as 
the Monitor, Keyboard and Mouse. 
These parts have to be connected to 
the CPU, for them to work.
Paint activity
Tejas double clicks on the paint icon. The paint activity 
window opens. 
Tejas first opens an existing file and plays with the colours. 
Then he creates his own painting. He knows that:
    The tools for drawing can be found under Tools.
    A set of tools is called a Toolbar.
    The various choices in any Toolbar are called the Options.
The tools and options that Tejas uses to draw a house are:
    New option to get a blank canvas.
    Shapes toolbar to get shapes like square, rectangle and triangle.
    Brushes toolbar to colour using the colour palette.
    Eraser to erase.
    Save option to save the painting.
    Print option to print the painting.
    Quit option to quit the activity.
Tejas: We have finished. Now can I paint using the computer? 
Jyoti: I want to listen to music.
Moz: Ok. Go ahead. You know how to start an activity.
 
 
The children spend their free period in the computer room. Tejas 
saves the painting and Jyoti sings the song that she has learnt.
This is what she clicks:
    Open option to select the song that she likes.
    Play to play the song.
    Pause to stop the song and practice that line. 
    Pause or Play again to continue the song from where it had 
stopped.
    Rewind and Forward to jump to a different part of the song.
    Mute to turn off the volume.
    Slider to change the volume.
    Stop to stop the song completely.
Moz: Very good. The song is melodious. The painting is very colourful.
Using a Music Player 
Jyoti double clicks on the music file. She knows that she 
can control the music player by moving the mouse pointer 
over the control buttons.
Jana Gana Mana.mp3
The small pictures that we see on the screen are called Icons.
The screen where all the icons are arranged is called the Desktop. 
Icons of activities that we use often are kept on the desktop.
The bar at the bottom of the desktop is called the Taskbar.
Exploring the Desktop
Dos and Don?ts
Tejas: Let us share our snacks and eat now. 
Moz: While we are eating let us play a word game. I will give you a few 
words and one of you has to say how they are related to a computer.
Tejas and Jyoti: Oh! This is going to be fun. Let us start.
Moz: Be Safe. 
Tejas: A computer works on electricity. Ask 
the teacher to turn the computer on 
or off.
 
Moz: Be gentle.
Jyoti: A computer is delicate. Press softly 
on the keys of the keyboard. Do not pull 
the wires of a computer.
Moz: Keep clean.
Tejas: A computer is sensitive to dust. Keep the computer and its 
surrounding area clean. Do not eat or drink near the computer.
Moz: Keep correct posture.
    Jyoti: Sit on a chair with proper height and sit straight. Sit at a 
proper distance from the monitor. Do not keep your hand 
on the mouse continuously.
Moz: That was good. Now let us go back into the 
computer room. 
Moz gives Jyoti and Tejas some worksheets about the Desktop.