THE BASICS OF LOGO

GETTING STARTED | APPLYING MATHS KNOWLEDGE | REPEATING | CREATING PROCEDURES

GETTING STARTED - lots of ideas that really work (without a computer!)

How do you get children started with a sophisticated programming language like LOGO?

Here are several practical ways to introduce the key concepts of LOGO, angles and distances without using a computer. In all cases, the idea is for the children to view everything from the perspective of the Turtle and imagine the turns etc. as if they are in it's nose!

These are the simple commands that you might use:

LT or LEFT followed by an angle in degrees
RT or RIGHT followed by an angle in degrees
FD or FORWARD followed by a number
PU or PENUP
PD or PENDOWN

• Use a Roamer!
• Make a short "Turtle Story" - Have the children imagine that they are the Turtle and that they have "escaped from the screen." As they are making their way across a desk (a card or paper turtle is useful), have them describe the turns they make and the things they see on either side. Reinforce the concept of the "turtle's perspective or view."
• Have a child guide another blindfolded child around objects in a hall area using the basic LOGO commands "forward", "right" and "left." Introduce distances. E.g. "Forward 3" would mean forward three steps. "Left 90" would mean turn a right angle to the left.
• Have the children verbally describe the route they take to reach their seat in class from the door. Counting their paces and noting each time they make a change of direction. (Are all the turns right angles or not?)
• Make a classroom map on the blackboard and draw routes around the room using straight lines. Can the children still describe routes when seen displayed on the board.
• Create basic shapes on squared paper. Have the children make a set of LOGO instructions to trace these routes.
• Pair children up with a screen between them and get one child to describe a drawn route using LOGO instructions and have the other child draw the shape on squared paper - When finished, compare the drawings. (Extend this by using Video Conferencing, whiteboard or Online Chat with another school.)
• Repeat the above activities but introduce the PENUP and PENDOWN commands to create gaps and spaces.
• Have the children make a simple maze on squared paper and have them write the instructions to navigate it in LOGO.
• Use Lego or Duplo characters within a model scene and choreograph their movement in LOGO instructions.

Use existing knowledge of bearings and compass readings - "Turtle Orienteering!"
This is an excellent activity since it is a great way of extending children's knowledge of compass bearings and map scales.

• Use a large scale OS map and have children describe the routes "as the crow flies" between key locations using LOGO instructions (lots of possibilities here!)
• Create a map or scan one in (Not O.S. maps - they are copyrighted) to use as a background on screen.

You could probably think of dozens of more similar activities....

It is also important to remind children about spaces in the instructions they write:

LT90 or FORWARD50 are both wrong - there must be a space between the command and the number:

LT 90 or FORWARD 90 are both correct.

INTRODUCING A COMPUTER

By now the children will be very keen to use the computer. Here are some simple, introductory ideas to get a class started on commanding the Turtle on screen.

• Make a simple maze on clear plastic using a permanent marker and blu tac it to the screen. Have the children estimate angles and distances in order to make the turtle navigate the maze.
• Have children make their own "overlay mazes" with features, treasure rooms etc. to be visited. Dangerous features could be "jumped over" using PENUP and PENDOWN! - Guaranteed fun!
• Use the picture import / background function of the LOGO program (MSW LOGO and FIRST LOGO are examples of programs that can load background images) to load a map through which the Turtle can navigate. Children can create their own harbours, treasure islands, street maps, etc. on a drawing program. (At Ambleside the children created a map of Barrow in Furness Harbour and used LOGO instructions to make a "boat" enter and leave the docks)
• Using the above "background graphic" idea, create a detailed "treasure island" on screen and provide children with a Pirate Story with secret LOGO instructions that guide the Turtle to the treasure.
• Have the children create their initials using LOGO instructions.
• Draw a house..
• A tree...
• A rocket....
• etc.....etc.....

It is a good idea to introduce the LOGO distance scale at this point. LOGO distances may equate to millimetres on a big monitor screen but children may benefit from making a "LOGO RULER" marked every ten units as they appear on the screen.

APPLYING MATHEMATICAL KNOWLEDGE

Creating Polygons

Children will have quickly grasped the fundamentals of drawing lines and estimating various angles and here is a great activity to apply some mathematical thought to the process of creating regular shapes.

• Have a child walk around the edges of an imaginary hexagon.
• How many turns did they make?
• Did they end up facing the same direction they started?
• Did they make a complete turn? (360 degrees)
• Try it with other regular shapes.

When making a hexagon a child will have made six sides and six turns as they walked and made one complete turn by the end. From this information the children should realise that, in the case of a regular hexagon, the amount of each turn around the edges can be calculated by dividing 360 (the full turn in degrees) by 6 the number of turns - - an answer of 60 degrees.

It is a simple step for children to create a polygon on screen with this series of commands:

fd 50
rt 60
fd 50
rt 60
fd 50
rt 60
fd 50
rt 60
fd 50
rt 60
fd 50
rt 60

Hardly elegant but effective!

What happens if there are more sides?

REPEATING - real programming!

The last example for drawing a Hexagon was rather long winded with twelve instructions used to create one simple shape.
Children should be encouraged to look for patterns or repeating in their instructions. In the example of the hexagon the first two instructions are "repeated" to complete the hexagon.
LOGO offers a command to simplify the typing - repeat:

repeat 6 [ fd 50 rt 60 ] This single line will create a hexagon since the commands within the square brackets are repeated 6 times.

Have the children create other regular polygons using only one line of LOGO.

For extra fun, repeats can also be "nested" within other repeats! - Try this:

repeat 36 [ repeat 3[ fd 90 rt 120 ] rt 10 ]

CREATING PROCEDURES

Procedures are the heart of LOGO and programming in general - procedures are little programs that can be called on again and again through one word and without typing them all out.

How do you create a procedure?

Creating a procedure is called "editing" and the command is edit. On MSW LOGO there is an edit option in the file menu. (On other versions of LOGO this may be called build or make and need to be typed in.)

A procedure must have a name so give it one - eg. edit "square. (avoid using LOGO words as procedure names!)

The following commands could define square.

to square
repeat 4 [ fd 100 rt 90 ]
end

After creating the procedure you will need to exit the edit screen and return to the main screen.

By simply typing square the turtle will draw a square on screen.

Try putting square within repeats, e.g: repeat 120 [ square lt 3 ]
or even another procedure:

to flower
repeat 60 [square rt 6]
end

Try these challenges:

• Create "Crystal Flowers" - Do this and you can tick off most of Year 4 QCA unit of work for LOGO!
• Create a procedure to create a tree - can you make an avenue of them using repeat?
• Create a single house and make a terrace from it.
• etc, etc....

The content and images within these pages is the copyright (c) of Mark Robinson and the children of Ambleside C.E. Primary School, 1999.