Centralia, Illinois

Math and Computers

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These procedures work with pcLogo, Harvard Associates, Inc.

to sqrepeat 4 [ fd 40 rt 90 ] end |
This is our first procedure. We are teaching logo its "first word". This procedure draws a size 40 square. |

to flower repeat 10 [sq rt 36] end |
This "flower" is made of 10 squares spun around in a circle. Notice that it is repeated 10 times and turns 36 degrees each time (10 x 36 = 360). Make sure Logo knows how to sq. |

to bouquet repeat 6 [flower fd 80 lt 60] end |
This bouquet is made of six flowers. Isn't it amazing what Logo can make with squares? Bouquet goes with flower and sq. |

to sqr :nrepeat 4 [fd :n rt 90 ] end |
This is a new procedure to draw a square. It uses a variable (changable number) :n . Now we can make different sizes of squares. SQ 20 makes a size 20 square and SQ 80 makes a size 80 square. |

to cnt :nif :n > 20 [stop] pr :n cnt :n + 1 end |
This procedure teaches Logo how to count (CNT for short). It uses recursion (CNT does itself over and over again). It follows the couning pattern (:n + 1). When you count you always add one to get the next number. |

to sqrs :nif :n > 150 [stop] sqr :n sqrs :n + 10 end |
This procedure combines counting and making differnt size squares. Use it with sqr. Instead of counting by ones it counts by tens (:n + 10) and instead of printing the numbers (PR) it makes squares (SQR :N) with the numbers. Pretty cool, huh? |

to poly :s :xrepeat :s [ fd :x rt 360 / :s ] end |
This procedure can make any regular polygon with any number of sides (variable :s) and any size side (variable :x). Why is the right turn (RT) 360 divided by :s ? |

to spiral :sif :s > 200 [stop] fd :s rt 119 spiral :s + 2 end |
This is an interesting sprial design. It uses recursion, a pattern of counting by 2 and turns 119 degrees, only one degree less than an equilateral triangle. This makes it look like it spins. |

to add :n :e :tif :n > :e [pr [----] pr :t stop] pr :n add :n + 1 :e :t + :n end |
What if you had to add all the numbers from one to a hundred? ...or to one thousand? |

to paintif button? 2 [pr [Paint Stopped.] stop] if button? 1 then pd else pu setxy mouse if key? [menu] paint end to menu ; Goes with paint. make "key rc if :key = "r [setpc 12] ; red if :key = "b [setpc 9] ; blue if :key = "g [setpc 32] ; green if :key = "y [setpc 14] ; yellow if :key = "w [setpc 15] ; white if :key = "0 [setpc 0] ; black if :key = "1 [setwidth 1] ; line width 1 if :key = "3 [setwidth 3] ; line width 3 if :key = "5 [setwidth 5] ; line width 5 if :key = "c [cs] ; clear the screen if :key = "f [pd fill pu] ; fill an enclosed area if :key = "s [pd repeat 5[fd 10 rt 144] pu] ; star end |
Teaching Logo how to paint with the mouse. |

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