← TurtleLab Lessons

TurtleLab Lessons

For teachers

The first five steps take students from “the turtle does what I say” to a piece of art that uses a loop, random, and if and else. Steps 6 to 12 add variables (drawn as boxes), blocks of their own (functions), loops inside loops, color as numbers, debugging, and a second capstone. Each step starts from a TurtleLab demo the students change; in most steps the demo is built into the page in a frame, so they never leave the lesson. The student pages never mention a teacher, a class, or grading, so a student can work through them alone. Everything about running them in a classroom is on this page.

Four of the steps end with a PDF made by TurtleLab’s PDF button:

  • Step 1 is a small first project, a PDF of the student’s initials. It shows you they can plan a drawing and make the turtle do exactly what they say.
  • Step 4 is a practice PDF. It shows you they can use a loop, random, and if and else together before the capstone.
  • Step 5 is the capstone, a piece of random art.
  • Step 12 is the second capstone, a picture that uses a box, a block of the student’s own and a loop. The last page of the PDF lists what the program is made of, with a count for each kind of block (variables, loops, blocks they made), which makes it quick to see at a glance.

  • Step 15 is the third capstone, an interactive picture: the program asks a question and uses the answer, and every click on the paper draws something where it was clicked, using a block of the student’s own and a loop. The last page of the PDF has a row for ask / when paper clicked, which makes the new part quick to check.

  • Step 16 is a guided build, a click game (“Catch the square”) that teaches the Math blocks and, or and not and asks if a click hit a target. It is not a capstone: the page gives the block that draws the square and an outline of the click handler, and the student builds the rest. It ends with a PDF too.

  • Step 17 is a guided build, a snake game (“Steer the snake”) that teaches the when [key] pressed and every blocks: the program listens to the keyboard and moves by a timer. It is not a capstone: the page gives the two blocks of their own (one draws the red square and comes back, one starts the game again) and an outline of the rest. It ends with a PDF too. The snake gets fatter, not longer, because a growing tail needs more memory than TurtleLab’s four boxes.

  • Step 18 is the fourth capstone, a game or toy of the student’s own. It needs at least two of the three ways of listening (a click, a key, a timer), a box that changes while it runs, an if with and or or, a block of their own used more than once, a loop and two colors. The page points at five samples on the Samples page (Keyboard painter, The bouncing turtle, Click flowers, Catch the square, The fat snake) to open first, and offers four themes. The last page of the PDF has a row for ask / when paper clicked / when key pressed / every, which makes the listening quick to check.

Steps 2, 3, 6 to 11, 13 and 14 are practice with no PDF to collect. Every step ends by telling the student to save a PDF to keep their own work.

The sequence

Step What students do
1: Your initials Plan on a grid, then draw their initials with exact moves, with no blocks of their own yet. Predict where the turtle ends and which way it faces. Walk between letters with pen up, set xy, set heading and pen down. Draw a frame and count its blocks.
2: Say it once Meet repeat with a square. Find turn = 360 ÷ sides.
3: Let chance draw Use random in a loop. Build confetti.
4: Choose a path Meet if and else through a coin flip. Trace a run on paper. Save a practice PDF.
5: Capstone: random art Plan and build a piece with all three. There is a one page planning sheet to print.
6: Variables: boxes that keep a number What a variable is, and why TurtleLab draws one as a box. Predict, then watch a slow program change a variable block by block (the real blocks, in a frame), and a house whose size comes from one variable.
7: Boxes that count A variable that updates itself: the + block is worked out first, then stored. Watch a box count and print, trace a doubling box on paper, a countdown, a spiral of their own.
8: Teach the turtle a word Blocks of their own (functions) with an input. A flower from one petal block; change the word once and every use changes. Then their name again: the initials idea of Step 1, now one block per letter (a letter that comes twice uses the same block), each letter its own color. Compare a B drawn two ways, 15 blocks and 9.
9: A loop inside a loop Nested repeat: the inside draws, the outside repeats and turns. Count the moves (12 × 4). The ring closes when laps × turn = 360.
10: Color is three numbers Red, green and blue from 0 to 255. Why 255: eight bits. Binary and hex with the color picker. 256 × 256 × 256 colors. A color made from a box.
11: Find the bug Four broken programs to fix, each with a hint and an answer: a triangle that does not close, a box that is never used, an if that can never be yes, a pen left up.
12: Capstone 2: boxes and blocks Plan with three sentences, then build a picture with a box that changes, a block of their own with an input, and a loop. Ends with a PDF.
13: Ask for a number The ask block: a question, a wait, and the answer in box1. Predict what a shape will do for 5, 3, 12 and 0. Why a second answer replaces the first, and how to keep one (store it in another box). Build a square from an answer.
14: Click to draw when paper clicked with the built in variables mouseX and mouseY. A program keeps listening after its last block until Stop. Predict where clicks land (the paper is -350 to 350 by -280 to 280), then build a dot painter.
15: Capstone 3: ask and click Plan with three sentences, then build a picture that asks a question, draws where it is clicked with a block of their own, and uses a loop. Ends with a PDF.
16: Catch the square and, or and not: predict what a click inside or outside a stripe gives, then ask “is the click inside this square?” with two stripes that cross. Build a game where a red square jumps to a random place each time it is clicked, with the score in box1. Ends with a PDF.
17: Steer the snake when [key] pressed and every: predict what presses of the arrow keys draw, then what a timer does by itself (the third tick of a growing spiral). Build a snake: it walks by itself, the arrows set its heading, eating the red square makes it fatter and the square jumps, going off the paper starts the game again. Uses and, or, speed and two blocks of their own. Ends with a PDF.
18: Capstone 4: make a game Open the sample toys and games first, then plan with three sentences (how the person plays, what the game does by itself, what a box holds and what the if decides). Build a game or toy that listens in at least two ways, keeps a box up to date, decides with and or or, and uses a block of their own and a loop. Ends with a PDF.

Slides and a worksheet. Two slide decks are for projecting, each with live TurtleLab frames, hidden answer slides (down arrow) and speaker notes (N): Step 1 slides and Steps 2 to 4 slides. There is also a one page Steps 2 to 4 worksheet to print (US Letter, hole punch margin): the turn table, the Step 3 numbers and the six flip trace. Its answers are in the answer key.

The steps come in four units, each ending in a capstone: Steps 1 to 5 (tell the turtle what to do), 6 to 12 (remember and reuse), 13 to 15 (listen to the person) and 16 to 18 (make a game). The contents page shows them as four colored bands (_data/turtle_units.yml, and a unit: line in each step). Students draw their initials without any blocks of their own in Step 1, on purpose, and meet blocks of their own in Step 8, where they draw their name again with one block per letter. Students who have not seen loops meet the need for one first (a square that takes eight blocks) and only then get the block. if and else comes after random on purpose: a coin flip is the easiest decision to understand, and students who find conditionals confusing can see one path or the other run, never both.

Assignment text to paste

Plain paragraphs and lists, so they paste cleanly into Schoology and Google Classroom. Change the wording to suit your class. The student pages never mention points, so the capstone rubric appears only here. Change it to suit your class.

Assignment: Your initials

Draw your initials with TurtleLab, then save a PDF.

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Shapes from one rule

Make one drawing in TurtleLab, then save a PDF.

  • Work through Step 2: https://learn.porttack.com/turtle-lessons/step-2-say-it-once/
  • Use only repeat, forward, right and set color.
  • Draw three regular shapes, such as a hexagon, an octagon and a shape with 12 sides. Each one is a repeat, and each is a different color.
  • Draw one rhombus: two forward blocks of the same length and two right blocks, inside a repeat of 2.
  • Every shape must close up.
  • Add a sticky note with your name.

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Answers: hexagon 60, octagon 45, 12 sides 30. A rhombus has two turns that add to 180 (60 then 120, or 120 then 60). Two different forward lengths make a parallelogram, not a rhombus. There is no rubric; ask if you want one.

Assignment: Random confetti

Make a confetti picture in TurtleLab, then save a PDF.

  • Work through Step 3: https://learn.porttack.com/turtle-lessons/step-3-let-chance-draw/
  • Build in a fresh TurtleLab tab, not a sample tab. A sample tab does not save your work.
  • Use a repeat to draw at least 80 dots spread over the whole paper.
  • Every dot has a random color and a random size, with some small and some big.
  • Add a sticky note with your name.

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Answers: set xy needs random -350 350 for x and random -280 280 for y; set color needs random 0 255 in all three slots; set pen size needs a random block, such as random 5 40. There is no rubric; ask if you want one.

Assignment: Practice PDF, Choose a path

Work through Steps 2, 3 and 4, then save a practice PDF.

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Capstone, random art

Make a piece of art in TurtleLab that uses a loop, random, and if and else, then save a PDF.

Rubric, 10 points:

  • A repeat that draws part of the picture: 2
  • Random that you can see in the picture: 2
  • An if with an else that changes something you can see: 2
  • At least two colors: 1
  • A sticky note with your name and what your loop, your random, and your if and else each do: 2
  • PDF attached: 1

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Your name, with blocks

Draw your name with TurtleLab, one block for each letter, then save a PDF.

  • Work through Step 8: https://learn.porttack.com/turtle-lessons/step-8-teach-the-turtle-a-word/
  • Make one block of your own for each different letter in your name, and use the same block when a letter comes twice.
  • No letter block may have a set xy inside it. The main program travels from letter to letter.
  • Give every letter a color of its own.
  • Build every letter piece by piece. Do not use the write block.
  • Add a sticky note with your name.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Capstone 2, boxes and blocks

Make a picture in TurtleLab that uses a box, a block of your own and a loop, then save a PDF.

  • Do Step 12: https://learn.porttack.com/turtle-lessons/step-12-capstone-2/
  • Build in a fresh TurtleLab tab. The demos inside the lessons do not save your work.
  • Your picture needs: a block of your own with an input that your program uses more than once, a box that changes while the program runs, a loop, at least two colors, and a sticky note with your name and what your box, your block and your loop each do.

(The student page lists these same five things for students to check. A rubric is yours to write. The last page of the PDF has a Count column for variables, loops and blocks they made, which you can use to check the first three quickly.)

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Capstone 3, ask and click

Make a picture in TurtleLab that asks a question and draws where you click, then save a PDF.

  • Do Step 15: https://learn.porttack.com/turtle-lessons/step-15-capstone-3/
  • Build in a fresh TurtleLab tab. The demos inside the lessons do not save your work.
  • Your picture needs: an ask block whose answer your program uses, a when paper clicked that draws where you click using mouseX and mouseY, a block of your own with an input that your program uses more than once, a loop, at least two colors, and a sticky note with your name and what your question, your click and your block each do.
  • Before you press the PDF button: press Run, answer the question, and click the paper a few times, so the picture is on the paper.

(The student page lists these same six things for students to check. A rubric is yours to write; ask and I will draft one. The last page of the PDF has a row called ask / when paper clicked whose Count should be at least 2, one for the ask block and one for the click handler.)

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Catch the square

Build a click game in TurtleLab, then save a PDF.

  • Do Step 16: https://learn.porttack.com/turtle-lessons/step-16-catch-the-square/
  • Build in a fresh TurtleLab tab. The demos inside the lessons do not save your work.
  • Your game needs: a red square that jumps to a new random place after every hit and not after a miss, a score in box1 that goes up by 1 for each hit, an if that uses and to ask two questions at once, a block of your own that your program uses twice, a loop, and a sticky note with your name that says in your own words what and does in your game.
  • Before you press the PDF button: press Run, catch the square a few times, so the picture is on the paper.

(The student page lists these same things for students to check. A rubric is yours to write; ask and I will draft one. The last page of the PDF has a row for Blocks you made and one for repeat / forever, which you can check quickly.)

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Steer the snake

Build a snake game in TurtleLab, then save a PDF.

  • Do Step 17: https://learn.porttack.com/turtle-lessons/step-17-steer-the-snake/
  • Build in a fresh TurtleLab tab. The demos inside the lessons do not save your work.
  • Your game needs: a snake that moves by itself (an every block), four when key pressed blocks that turn it, a new red square at a random place when the snake reaches the old one, which also makes the snake fatter, the game starting over when the snake goes off the paper (an or), an and in the test for reaching the square, two blocks of your own that your program uses, and a sticky note with your name that says in your own words what every does in your game.
  • Before you press the PDF button: press Run, click the paper once, steer the snake and eat a few squares, so the picture is on the paper.

(The student page lists these same things for students to check. A rubric is yours to write; ask and I will draft one. The last page of the PDF has a row for ask / when paper clicked / when key pressed / every, a row for Blocks you made and one for if / if else, which you can check quickly.)

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Assignment: Capstone 4, make a game

Make a game or a toy in TurtleLab, then save a PDF.

  • Do Step 18: https://learn.porttack.com/turtle-lessons/step-18-capstone-4/
  • Build in a fresh TurtleLab tab. The demos inside the lessons do not save your work.
  • Your game needs: at least two of the three ways of listening (when paper clicked, when [key] pressed, every), a box that changes while it runs, an if that uses and or or, a block of your own that your program uses more than once, a loop, at least two colors, and a sticky note with your name that says what your game is and how to play it, in your own words.
  • Before you press the PDF button: press Run, click the paper once, and play for a little while, so there is something on the paper.

(The student page lists these same things for students to check, and four themes to choose from. A rubric is yours to write; ask and I will draft one. The last page of the PDF has a row for ask / when paper clicked / when key pressed / every with a count of at least 2, and rows for Blocks you made, repeat / forever and if / if else, which you can check quickly.)

Turn in whatever you have 10 minutes before the end of class, even if you are not finished.

Press the PDF button in TurtleLab and attach the PDF to this assignment.

Substitute day

  • Skip Step 1.
  • Students work through Steps 2, 3 and 4, about 10 minutes each, then start Step 5.
  • Students turn in a PDF of whatever they have 10 minutes before the end of class, finished or not. Students who are not finished can keep going next class if you let them. The capstone is due at the end of the next class.
  • The substitute does not need to know how to code, and does not need to check anything. Each step tells students how to check their own work.
  • Optionally, print the Step 5 planning sheet for students who like to sketch on paper. It is one US Letter page.
  • Frames and sample tabs do not save. Steps 2, 3 and 4 show their samples in frames inside the page, and a frame has no PDF button (students use Open full size under it, which opens the sample in a tab of its own, and press the PDF button there). If students build their own work in a frame or a sample tab, a refresh puts the sample back and loses it. Remind them to build the confetti and the capstone in a fresh tab at https://learn.porttack.com/turtlelab/, or to press Ctrl+S now and then.

If students get stuck

  • The Guide link at the top of TurtleLab explains every button. Pressing and holding a block shows a tip.
  • Blocks disappeared? Press Undo (the curved arrow, or Ctrl+Z).
  • Program will not stop? The Stop button always works.
  • A key does nothing? The page has to be listening to the keyboard: press Run and then click the paper once (in a frame on a lesson page too). Typing in the Logo box or a sticky note is typing, not a key press.
  • The snake crawls? Put speed 4 (instant) under Start, so the blocks under every run all at once.
  • A red outline means that block has a problem. The message is under the drawing.
  • Cannot find the saved PDF? It is in the Downloads folder.
  • Students can ask a neighbor for a hint, then keep their own work on their own screen.

The write block

TurtleLab has a write block (Notes palette, next to the sticky note) that draws words in a single line, in one of seven fonts. It can draw letters for a student, so the student pages for Step 1 (initials) and Step 5 (capstone) tell students to skip it. It is not in the Pen or Turtle palettes on purpose. If you want it off the table for an assignment, add this line to the assignment text:

Do not use the write block in this assignment. The letters and the picture have to come from your own blocks.

Or turn it off with a link. Give students https://learn.porttack.com/turtlelab/?nowrite=1 instead of the plain TurtleLab address. On that page the Notes palette has no write block (and no set font or set curve, which only matter with it), and a program that has one, opened from a file for example, will not run: the block is outlined and a message says it is turned off. The Logo box refuses the write word there too. The Step 1 page already sends students to that link. It lives only in the address, so a student who types the plain address gets write back; the PDF does not show which address it was made at. Use the line above as well if it matters.

It is fine, and fun, for names on a finished picture and for the embroidery samples.

The Logo box

TurtleLab has a Logo button (the letters fd) that shows the blocks as Logo, the language the turtle was made for. A student can type in that box and press Run Logo to draw what they wrote, with either forward or fd. Two things to know when you grade. What a student types there is not saved anywhere, and it is not in the PDF. The PDF has the blocks and the drawing that is on the paper, so a drawing made by typing Logo will not match the blocks beside it. If you want the blocks, tell students to build the assignment with blocks. The Logo box is good for exploring, and for students who already know a text language.

It also has an Open in real Logo button, which is mostly for you when you teach: it opens the program (the blocks, or the Logo a student typed) in JSLogo, a real Logo interpreter kept on this site, in a new tab, where it runs at once. Project that tab to show the same program as blocks, as TurtleLab’s Logo, and as real Logo. The program is translated for JSLogo, because the two Logos differ a little (arcs, colors, and what happens on a clean), and anything JSLogo cannot do is left out with a note at the top. Nothing is sent to another website, and JSLogo keeps nothing between visits.

What is in the PDF

The PDF button saves a PDF with the blocks and sticky notes, laid out the way they are on the student’s screen, and the drawing with the turtle drawn where it stopped (so you can see which way it was facing) and a grid of x and y numbers on it (so you can check where each line is). A small program has the blocks above the drawing on one page. A thin, taller program has the blocks down the left of the page with the drawing beside them. A wide or very long program has the blocks on page 1 and the drawing, bigger, on page 2. All so the writing in the blocks stays readable. A picture of the drawing with the blocks inside it is attached to the PDF. Open it in TurtleLab (press Open, or drag the PDF onto the page) and the student’s blocks come back, so you can run their program. A sticky note holds about 300 letters. The PDF button zooms the drawing to fit first, so a drawing that ran off the edge of the paper is all there.

Samples never read or write what a student saved. That is on purpose, so a sample can never wipe out someone’s saved work.