ICT at key stages 1 and 2    (Year 4)

• Show the class how a floor turtle can be programmed to move in a square and write the instructions on the board - forward 4, right 90, forward 4, right 90, forward 4, right 90, forward 4, right 90. Repeat the activity using a repeat loop - repeat 4 [forward 4, right 90]. Discuss with the children their previous experiences of using these techniques with a floor turtle.
• Introduce the children to the screen turtle. Talk about the direction the turtle is facing and how it moves. Type in some instructions to show the turtle moving. Discuss spaces between command and number, and the use of the return key. Introduce them to the clear screen command. Again type in the instructions for drawing a square, but use forward 100 instead of 4. Discuss with the children the different step size that a screen turtle uses. Discuss the differences between using a floor turtle and a screen turtle. Remind the children that instructions are relative. Explain to them that they are going to make the screen turtle follow a number of instructions.

• Prepare a worksheet with a few simple sequences on it. These could include:
  • forward 100, right 90, forward 100, left 90, forward 100, right 90; forward 100, left 90, forward 100, right 90, forward 100, left 90;
  • forward 150, right 90, forward 150, right 90, forward 150, right 90, forward 150, right 90;
  • right 90, forward 50, left 90, forward 50, left 90, forward 50, right 90, forward 50, right 90, forward 50;
  • forward 200, right 120, forward 200, right 120, forward 200, right 120.
  Ask the children to predict what will appear on screen when these instructions are entered and give them a chance to work in pairs at the computer to test their hypotheses. Remind them to send the turtle 'home' before beginning each set of instructions.

• Provide two examples of letters (eg E or M) that can be drawn with the screen turtle using only 45 or 90 degrees; use graph paper (1cm²) to draw the letters. Show the class how to draw the two letters and explain how each square on the graph paper measures 50 screen turtle steps. Demonstrate how to write instructions to produce the two letters on screen.
• Ask children to draw the first letter of their name on a piece of graph paper and get them to write the instructions for the screen turtle. When children have completed their sequences produce the example letters, but use penup and pendown to move the turtle to the left of the screen before doing the first letter and then to the right of the screen to do the second letter. Show the children how to print their work. Divide the children into pairs and ask each pair to create their initials on screen and print the results.

• Prepare a worksheet with a few simple repeat sequences on it. These could include:
  • repeat 4 [forward 100, left 90];
  • repeat 3 [forward 150, right 120];
  • repeat 6 [forward 100, right 60];
  • repeat 360 [forward 1 right 1];
  • repeat 10 [forward 50, right 36]
  Discuss with the children their previous experiences with a repeated sequence and demonstrate the instruction: repeat 5 [forward 80, right 108]. Ask the children how many sides they think the shape will have. Type the instruction into the computer and show the children what happens.
• Using the prepared worksheet when the instructions are entered ask the children to predict what will appear on screen and give them a chance to work in pairs at the computer to test their hypotheses.

• Write the following procedures into the computer and save them: square, equilateral triangle, staircase, pentagon. Give the procedures arbitrary names, such as 'Pooh', 'Tigger', 'Eyore' and 'Piglet'. All these sequences have been used in previous lessons.
• Show the children the screen turtle drawing a square, without using the procedure you have written. Then move the turtle using penup and pendown and repeat the square. Explain how it would make things easier if the turtle could learn a word to draw a square. Tell the children that you have taught the turtle four new words and demonstrate the one that draws the square. Show them how they could change the numbers in the procedure to make a bigger square. Divide the class into groups and let them test all four procedures. Ask them to try changing the size of the sides and the steps.

• Use the procedures from the last task to write a new procedure called 'hum'. Use the square (Pooh) and the triangle (Tigger) and penup and pendown to draw a simple house. You will need to rotate the turtle by 60 degrees before 'putting' the roof on. Show the children that every time you type 'hum', the house appears. Divide the children into pairs and ask them to write their own version of 'hum', maybe changing the size of the square and the triangle. When they have done this ask them to use 'hum' to create a number of houses and ask them to print their results.

• Explain to the class that they will create a number of 'crystal flowers' on screen. Tell them that they will need to write a number of procedures, such as square, rectangle, triangle, pentagon, and that they will combine the shapes into a larger procedure; the larger procedure will allow them to rotate the shapes 360 degrees and produce a flower. An example procedure might be: repeat 36 [square, right 10] which would produce 36 squares with a rotation of 10 degrees in between, producing a flower effect.
• Ask children to work in pairs to create their own flowers and get them to print out their work. They could colour in their flowers and produce a garden display for the classroom.