What is Squeak School Stuff Kids Squeak Media Developers Site Community Contact



Drive A Car
The first Squeak Etoys project for children.
How they design, build, get to tun, and learn to drive their car.
A favorite first Squeak Etoys project for 9, 10 and 11 year olds is to design a car they would like to learn to drive, make the car with computer stuff, and play with it by themselves and with others. Then they can make it into a robot car, race it, and then learn how to make fun animations.
This project introduces them to many of the Etoy materials and tools (and it is also a good way to explain how Squeaking works to adults).
The Squeak Etoys desktop is mostly bare to make the most room for the children's work and play. There are popout flaps that hold supplies, suggestions and help, links to mentors, navigation aids to find and save projects and provide access to tools such as the painting kit.
The paint kit
There are 8 parts to this project:

o Paint the car
o Make A Simple Script
o Steer The Car Using The Script
o Make a Steering Wheel and Attach It To The Car
o Get Advice About How To Make Car More Controllable
o Draw A Test Track and Make A Sensor On The Car
o Add More Scripting To Make Sounds When Off The Track
o Pass The Driver's Test

Paint The Car
The children start by thinking about what their car should look like and then paint it as seen from the top (this is a nice project for this age in itself).
They press Keep when they are finished with the painting.
If the pointer hovers over their object, a "halo of handles" with useful controls appears.
Their painting is a graphic object and can be resized (using the yellow handle) rotated (using the blue handle), and repainted (using the grey handle).
Then they "open up" the car to "see" its properties with the light-blue handle.
For children of this age, the textual form of these properties doesn't look as exciting as the iconic car that can be directly manipulated.
The "Montessori game" here is for the children to get most of their pay-off playing in the hand-eye arena, while gradually and subliminally gaining fluency and appreciation of the power of symbols.

But, the symbols can make the car do things! For example, they can find the property called "heading" and click on the up-caret to make the number bigger, and the car will turn in response.

If they turn the car by hand using the blue handle, the value of the heading property will change.
The visual image of the car pointing in a particular direction and the property called heading are two different views of the same idea. The visual image of the whole car and the viewer of the car are two different views of the idea called "car".

The "two different views of the same thing" idea is made clearer by giving the car a name such as "red car".

Some of the properties are behaviors. For example, there is a behavior called "forward by". If the exclamation point is clicked on, the behavior will be triggered, and the car will move forward by the distance given in the number.
There is another behavior called "turn by". Triggering this will turn the car by this number of degrees.
Make A Simple Script
Behaviors can be made into a script by dragging them out and dropping them on the desktop. Let's drag out a "forward by" tile and a "turn by" tile.
The script can be triggered to run over and over by clicking on its clock.
We see that doing car forward by 5 and car turn by 5 over and over seems to move the car in a somewhat circular motion.
We can find out exactly what the car is doing by dropping its pen - which will trace its path : by going to the pen category in the viewer

and setting the property "pen down" to "true".

In fact the car seems to draw a perfect circle.

Steer The Car Using The Script
If we change either or both of the numbers in the script, the car will still draw circles, but of different sizes.
Clearly, something interesting has been captured here by these 10 year olds. Going a little and turning a little over and over seems to make circles. Adults may remember something complicated about x2 + y2 = r2 and wonder why this way is so simple. It's because when looked at from the view of an ant on the rim of a circle, a circle is just a track of constant curvature. All the ant has to do is keep its moving and turning going at the same rate to trace out a perfect circle.

This way of looking at geometry is called "the differential geometry of vectors" and is the main mathematics used by science. It is used by scientists because it is simpler and more powerful than the general math taught in K-12. It is worth pondering this paradoxical irony.

But the children are only peripherally interested in circles at this point. They want to get on with making their car so it can be driven.

This is a really important point. "The play's the thing" here. It is our job to make lots of little aha's happen during the play, not to disrupt the play. We are not trying to teach them specific math at this point, but how to be real mathematicians. The children have to play with math to do this.

First, they find that they can steer their car by changing the number after "turn by".
The bigger the number the larger the rate of turn. Zero goes straight. Positive goes right, negative goes left. But this is weak tea. Real cars are steered with a steering wheel.
Make a Steering Wheel and Attach It To The Car
They paint a steering wheel.
This is the same kind of object as the car, but it has a different costume. They name it "steer" and recall that it also has a heading. They try turning the steering wheel and notice that the property "steer's heading" gets larger and smaller, goes negative, etc.
Then they are shown that they can pick up the name "steer's heading" of the direction numbers that are being put out by the steering wheel and drop it over the number where "turn by" gets its input. All of a sudden the heading of the steering wheel is now controlling the car!
There is a huge visceral flash at this moment: the name stands for the number! This is a wonderful way for these 10 year olds to learn about variables -- a subject about which many adults retain confusion -- in a painless and powerful setting. Most children do this learning from a single exposure to this example.
The car is a bit difficult to control because the numbers from the steering wheel are too large and the car oversteers. The children will ask how to make it better. In the classroom this is an opportunity to show them something neat. But what if they are at home doing this by themselves or they have a teacher who is not confident about this kind of mathematics?
Get Advice About How To Make Car More Controllable
The children are connected to the Internet, and part of the Squeak system is a registry where children who have already done projects can sign up to be mentors and colleagues. Colleagues are represented by badges with their name and picture on it.

Our child, Beth, finds in the "folder of friends" that Yasie, who lives in Kyoto, did this project the previous year.

Her badge has a glowing halo indicating that she is online, so Beth contacts her by pushing on the chat button.
Both text and voice chat are provided. They get acquainted and finally Beth asks how she can control her car better. Yasie says "let me see your screen", so Beth pushes the Share button at the bottom of her desktop.
Now Yasie gets a window on Beth's world and can interact with her.
Their pictures and names now show up on their cursors. Yassie shows Beth that she can do some arithmetic on the number coming out of the steering wheel if she clicks on the little triangle.
This pops out an example expression. A click on the "+" shows other possible operators.
Yasie explains that "/" (division) will work nicely here: "try dividing by 3".
The number after the "/" is clicked up to "3".
Now Beth tries her steering wheel again and finds that the car is much more controllable.
For the first time in her 10 years on earth, she has just learned what division is good for!

Multiplication and division have no importance in most children's lives. They don't need them to divide up M&Ms or pizza. Multiplication and division are used for scaling things, but children have very little (usually nothing) that needs scaling. Here they do. There is a direct relation between mathematics and the play the children want to do.

Now that Beth has a nicely working car, she and Yasie decide to play a car game. Yasie takes the car she made and drops it and its steering wheel onto the shared world
and it is instantly transmitted to Beth and drops on her desktop.
Yasie tells the shared window to go to full screen so she has just what Beth has on her screen.
Now they get started on some serious play. How about a game called "Chase"?
Even better, how could a car be made to act like a spaceship?

30 years ago this was a fantasy about how children would learn science and math some day on their own notebook personal "Dynabooks". After many years of building and testing these ideas, today this scenario is real. For the last several years hundreds of children have been building their own "kinetic art-math" just like Beth and Yasie in this dynamic media personal computing system.
We have just finished the first complete project for most children. To the child the result is a working toy made from working toys. To those who are mathematically savvy, the children have started to learn about variables, processes, and differential models in a very deep way.