Key Focus 2 - Getting Into Shape - TTS InO-Bot Scratch Teachers Manual

Key Focus 2 – Getting into shape
InO-Bot has a lift and lower pen carrying mechanism.
This feature is really useful to see where InO-Bot has
moved. Drawing shapes is a good activity to develop
programming skills using repetition and also maths
knowledge.
The first challenge is to make InO-Bot move in a square
shape.
Notes:
The 'Movement Complete' block is available when
Scratch for InO-Bot is first launched. The block ensures
the next command is not sent to InO-Bot before the
previous command is completed. Bear in mind that
InO-Bot is being controlled live by the PC.
InO-Bot has large wheels and these may account for
some small errors. Although not mathematically
accurate, turns may need to be increased or decreased by a degree or two. The
accuracy of movement may also be affected by the type of surface InO-Bot moves over.
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The example program (shown above) works but isn't
very efficient. Using repetition can help reduce the
number of instructions required. "Forwards 10 cm
then spin right 90 degrees" is repeated four times.
The example (right) shows what this would look like.
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Now use InO-Bot's pen holder to see what shape has
been drawn. What other regular polygons can the
children create?
Try drawing an equilateral triangle. This is actually
quite challenging and can provoke useful discussions
about internal and external angles.
You may also wish to talk about the relationship
between the number of sides and the angles, e.g.
A square - 4 sides, external angle 90°
A pentagon - 5 sides, external angle 72°
An octagon - 8 sides, external angle 45°
Tip: For each of the above multiply the number of sides by the angle.