[Squeakland] XO laptop: EToyChallenge Step 7

[Kazuhiro ABE]

Hello, Young-Jin Lee,

Bert already gave you a good hint.
I have another metaphor to solve this kind of problem.
Now, you are riding a bicycle and a white line is painted on the road.
If you must be keeping the edge of line (not on the line), what do you
do?
Or imagine other things. For example, a thermostat of an electric
heater, an automated speed control system of a car and etc. These are
controlled by same mechanism called feedback.

On the other hand, you found the solution that used two eyes.
There are many many viewpoints to solve one problem. But my tutorial
seems to force you and your son to choose only one viewpoint. It was a
limitation of usual static tutorial. But you can change the rule of
this tutorial because it was created by Etoys itself. You can get
halos of the car with alt key plus left click.
So please show your idea to your son and think together about other
solutions after finished this tutorial.

Regards,
Kazuhiro Abe