Unit 4E:
Modelling effects on screen
Roger Young © 2003
www.kudlian.net
Learning Objectives
Children should know:
that the screen turtle can be moved on screen
that the instructions given to a floor turtle
can be used by the screen turtle
Roger Young © 2003
www.kudlian.net
Children should also:
recognise that the same language is used to
programme a screen turtle and a floor turtle
recognise that the commands used in LOGO
are similar to the ones used with the floor turtle
recognise that the screen turtles reactions are
shown by the line it draws
Roger Young © 2003
www.kudlian.net
Introducing Logo
Try some fun activities using the computer
Use a simple
floor
turtle
such as
Some of
these
are free
Swallow
Systems
Pixieto Logo
http://www.kudlian.net/movies/terry_menu.html
Children
can be
introduced
type activities at an early age
Roger Young © 2003
www.kudlian.net
Exploring Shapes
Drawing Squares:
Use a floor turtle to draw a square
Write down the commands used
Show what happens if you use the
same commands with the screen turtle
Write the command line again using
commands suitable for the screen turtle
Roger Young © 2003
www.kudlian.net
Letters and numbers
Ask the children to draw letters
using a screen turtle.
Roger Young © 2003
www.kudlian.net
FD 148
RT 135
FD 78
LT 90
FD 78
RT 135
FD 148
Children can use graph paper
to plan their letters and numbers
Start with the first letter of their name, but
remember that a letter E is a lot easier to
plan than a K or R.
Roger Young © 2003
www.kudlian.net
Using
Repeats:
Exploring
Shapes
Get the children to look at the command
line used to draw a square
Can they see any patterns?
Write out the command line again using
the REPEAT command
Roger Young © 2003
www.kudlian.net
Using
Repeats:
Exploring
Shapes
FD 150 RT 90 FD 150 RT 90 FD 150 RT
90 FD 150 RT 90
Becomes
REPEAT 4 [FD 150 RT 90]
Roger Young © 2003
www.kudlian.net
Procedure
s
What is a procedure?
Answer: A set of instructions
What can you do with it?
Answer: We can give it a name, save
it and use it again and again
Roger Young © 2003
www.kudlian.net
Procedure
s
To SQUARE
REPEAT 4 [FD 100 RT
90]
Creates a procedure
called Square
Roger Young © 2003
www.kudlian.net
Next use the procedure SQUARE as
part of another set of commands
SQUARE
RT 90
FD 150
LT 90
SQUARE
RT 90
FD 150
LT 90
SQUARE
Roger Young © 2003
www.kudlian.net
Creates three identical squares in a row
Logo Can Be
Fun
Logo can be great fun.
There are many Logo applications available for
use inthe
schools,
have
a look
at Terryof
the
Turtle 2.
Once
children
have
experience
creating
REPEATS and PROCEDURES, they can easily
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create complicated
and beautiful patterns and
structures.
Roger Young © 2003
www.kudlian.net