CBSE Class 3 Computer LOGO Procedures Worksheet

LOGO Procedures

Logo provides two modes of operation to its users.

1. Immediate mode
2. Procedure mode

Immediate mode that means whatever is typed in the input box is executed at once.

 The logo is a sequence of LOGO command designed to complete a specific task.

The different between a procedure and a command is that a command is already defined in LOGO but a procedure is a set of command defined by the user.

PROCEDURE MODE

The command to enter the procedure mode is “To” followed by the procedure name.

To write a procedure, follow the given steps.

1. Type ‘To’ <space run> name of the procedure in the command input box. For example, on typing command TO SQUARE, the To Mode window opens.
2. Now, type the command in the Input space and click the OK button.
3. When you finish typing the commands, Type End in the input space and press the ENTER key click the OK button.

HOW TO EXCUTE A PROCEDURE

To get square drawn, you need to execute or run the procedure. To execute a procedure, follow the given steps:

1. Type ‘name of procedure’ in the input box. For example, SQUARE. Press Enter.

To draw two squares

PU RT 90 FD 60 LT 90 PD

Let us consider another example, suppose you want to draw a row of 4 pentagons on the graphic area. To do this, follow the given step:

1.Type ‘To PENTAGON’ in the Input Box.

2.Type the command REPEAT 5 [FD 30 RT 72] END in the To Mode window.

3.You will get the message ‘PENTAGON defined’ in the recall list box.

4.Type PENTAGON and press enter key. The pentagon will get displayed on the screen.

5.Now to draw other pentagon, you have to position the turtle. To position the turtle define another procedure as follows :

To POSITION

RT 135 PU FD 60 PD LT 90

END

6.You will get the message ‘POSITION defined’ in recall list box.

Type the following command

REPEAT 4 [PENTAGON POSITION]

A row of 4 pentagons will get drawn on the screen as shown in the figure.

HOW TO SAVE A PROCEDURE

To save the procedure files:

1.Select and click file on the title bar. A drop down memory appears. Click on Save.

2.The Save As dialog box opens.

3.Type the file name in the file name box and click on Save.

4.The logo file would be saved with .LGO extension. For example

SQUARE.LGO.

HOW TO LOAD A PROCEDURE

To load a procedure, follow the given steps

1.Select File menu and click on the Load.

2.The Open dialog box appears.

3.Select the file and the file name is displayed in the name box.

4.Click on Open to load the procedure.

5.The procedure file is loaded into the computer memory and saved.

6.Now, you can use the procedure by typing in the procedure name to execute it.

7.When you type the procedure name in the input box, you will get the following message.

Q1:- To prepare a model/chart of keyboard depicting all the keys. You may give the base of a thermocol sheet to your chart

1-Fill in the blanks:----

a- CU stands for control unit .

b- MU stands for memory unit .

c- A printer is used to print any document or picture on a sheet of paper.

d- A speaker is used to listen to music and other sounds playing on the computer.

e- A keyboard is used to write or give instructions on a computer.

f- Printer produces a printout or hard copy.

g- ALU stands for Arithmetic Logical Unit .

h- Mouse is used to point and select the items displayed on the monitor.

i- UPS stands for Uninterrupted Power Supply

j- Monitor displays the output.

2-Write TRUE or FALSE:-----

a- Speaker is used to record any voice on the computer.
Answer: FALSE

b- The printed sheet of paper is called soft copy.
Answer: FALSE

c- CPU stands for Center Processing united.
Answer: FALSE

d- Laptops have in-built speakers.
Answer: TRUE

3-Who am I?

a-I have 104 keys.                                      KEYBOARD

b- I control all activities of the computer.   CONTROL UNIT

c- I am a pointing device.                           MOUSE

d-I am playing music for you.                     SPEAKER