Page 62 - Computing E-Book Grade 3

The City School 2021-2022

4.2. Getting Familiar with Turtle Commands

The turtle can only follow instructions that he understands. If you give the turtle an
instruction that he doesn’t understand, he’ll say something like I don’t know how to do that.

Here are some instructions that the turtle already knows.

Procedure Example Description

Forward (number) FORWARD 100 the turtle walks forward 100
screen dots

BACK (number) BACK 100 the turtle walks backward
100 screen dots

LEFT (angle) LEFT 90 the turtle turns left

CLEARSCREEN CLEARSCREEN The turtle erases everything
that he has drawn and goes

back to where he started
PENUP PENUP The turtle moves without

drawing a line
PENDOWN PENDOWN The turtle moves and draws

the line all the way

When you say FORWARD 10, the turtle moves forward 10 screen dots. These screen dots

are also called picture elements or just pixels. The bigger the number, the more the turtle
moves. But what does the number that follows RIGHT and LEFT mean? It’s the number

of degrees to rotate. Here are some pictures to help you remember. For every RIGHT
instruction, there’s a LEFT instruction that does the same thing.

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