About the Level 3 Commands

Welcome to Level 3! At this level we introduce commands that will allow your children to control the turtle even more. With a little practice, they will be able to perform some “turtle magic.” The Disappearing Turtle, The Homing Turtle, and The Trackless Turtle will become featured actors in these next events

Remember that you can press * at any time to save a child’s picture.

Hide/Show Turtle - T

There may be times when the turtle is a nuisance on the screen. It may spoil a perfect picture by its presence or make it hard to tell if two lines meet exactly.

Pressing the T key makes the turtle disappear; pressing it again makes it reappear. The same key hides or shows the turtle. This is called a “toggle” key. Children can think of how a light switch turns a light bulb off or on. Can they think of other toggles? Have them think of the power button on a television remote control or the button that turns the car radio on or off. Expect some exploratory play with the T key at first and later watch for more planned usage.

Tip: Hide the turtle before printing pictures or taking a screenshot to prevent it from being included in the design.

Pen Up - U

This command tells the turtle to lift its drawing pen. Now the children can move U the turtle around the screen without its leaving a trail. They can use this command to draw disconnected designs in different parts of the screen. For example, they could write their name using the turtle, with spaces between the letters. Note that when U is pressed to pick up the turtle’s pen, it will stay “up” until told otherwise. There is no need to press U before each command.

Pen Down - D

As you might guess, you need a command to put the turtle’s pen back down. Pressing D will place the turtle’s pen back in operation and it will stay down until further notice. If the turtle suddenly stops drawing lines, press D to give the Pen Down command. The U key may have been pressed accidentally.

Home - H

As your children probably already know, the turtle’s Home is in the center of the Graphics window. It returns there whenever they start a new picture. Now they can move the turtle Home simply by pressing the H key.

The turtle will draw a line back home unless its pen is up. Therefore, if the children want to move the turtle back Home without leaving a line, they must first press U to pick up its pen, H to return the turtle to its Home position, and D to put the pen down again, ready to draw.

The H command leaves the turtle pointing straight up. The children may find that this command is not interesting to include in patterns because it fixes the turtle’s heading. This in itself is a powerful idea that you might want to discuss with them.