Introduction

Discuss control with the children. When might they have seen examples of control?  Talk about examples such as traffic lights, automatic doors which repeat the same commands.  Why is it important that they keep repeating?  How do they think computers can help control systems?

 

What is Logo?

Open Logo from Purple Mash. Find it in Tools > Computing.

 

 

What looks different in this program? (compared to other programming tools like 2Go) Establish that there are no arrow or number controls. If there are no arrows and numbers, how do you think we make the robot move? If they spot the command box, discuss what the letters might stand for. Focus on the basic commands; fd, bk, lt, rt, cls.

Explain that these are the basics of a programming language called Logo. Just like humans, computers can understand many different coding languages,

These could be:

 

The buttons on a Bee-Bot:

 

 

Blocks in Scratch:

 

Written coding languages like Python:

Getting started with Logo

Children may have had a brief introduction to Logo in Year 1, if they have completed our Year 1 unit of work Programming Direction. That unit has one lesson that introduces some basics in preparation for this unit.

Logo is a nice simple coding language to get started with that uses word and number commands instead of arrows etc.

Take a look at the main screen with the class. Ask them - have you used this before? What can you remember? How can we write code to give instructions in Logo?

 

 

Show how you can click on the commands in the list of commands on the right of the screen to add it to the command line. Or you can just type them in, but either way, you need to press Enter to run each command or click the play button at the top of the screen. Each command makes the arrow do things. Another name for the arrow is a screen turtle.

Add ‘fd’ and press Enter, why doesn’t anything happen?  

 

 

Establish we need a number as well. Add another ‘fd’ and then a number (make sure there is a space between the command and the number).

 

 

Turning on the grid feature is really useful at this point, and is something we'd recommend the children use at all times, as the squares correspond to the number of steps you type.

 

 

How could we turn the screen turtle?  Lt and Rt will do this, but again we need to add a turn number. Establish that this is the number of degrees the arrow will turn, although it is not necessary to get deep into this, they just need to understand that it is a unit of measurement for turning and angles. Stick to two key numbers as options for them when turning - 90 and 45 degrees, and 90 degrees in particular as being a quarter turn.

How could we draw a square? What would be the first command?  Take their suggestions and demonstrate, emphasising the need to type in 90 degrees for the corners.

 

 

Choose your turtle

The term screen turtle refers to the cursor that you program to move around the screen. In many Logo programs, this is an actual turtle sprite, as it was traditionally. However, the Purple Mash version of Logo gives you a choice of many different sprites for your turtle, including some turtles!

Show the children how you can pick your own by clicking the arrow icon at the top of the screen.

 

 

You should be taken to the default category of 'Turtles', which are all birds-ey-view type images, and are ideal. But you can add any Purple Mash clipart images from the drop-down box.

 

 

Main task

Give the children some time to experiment with Logo, ask them to try out Fd, Bk, Lt and Rt and investigate what the command Home does (they’ll have to type ‘Home’). This sends the screen turtle (arrow) back to where it started. There is also a reset button at the top of the screen which clears all drawn lines and returns the arrow to the centre of the screen. 

 

 

Clear their screen and have a go at drawing a simple shape like a rectangle with their screen turtle. Ask them to have a go drawing rectangles of different sizes and different orientations (tall and thin, wide and short). Some children might be able to attempt a triangle but might need help with the angles.

 

Plenary

Recap the commands they now know in Logo. What was difficult? Did they get better at estimating the distance of movements? How does the background grid help with this? What happens if you make a typing or spelling mistake when you give a command? Why?  Computers only follow exact instructions, they don’t usually interpret information (unless programmed to do so).  What is a programming language?