Burger Lab teaching notes

About these lessons

Three lessons of about forty-five minutes each, for ages ten to fourteen, with a fourth for students who have met JavaScript. Students build a burger and cook its patty until a thermometer says it is done, then run the kitchen that serves it: first by hand, then by rules written as sentences, then by a program. Each lesson has one idea, ends with something the student did and can explain, and only uses what the lessons before it taught.

You do not need to have used Burger Lab before, and you do not need to cook. Everything you are asked to say or point at is written here in the words that are on the screen. The steps were walked through in the lab with real clicks when it was built, and are walked through again whenever it changes.

How to read this guide

1. Say what to tell the class, in a sentence or two. Use your own words if you like.
2. Students do the steps, in order. Read them out or put them on the board.
3. On their screens what you should see when you walk round. If a screen does not look like this, that student needs you.
4. If it goes wrong what usually goes wrong at this step, and what to say.
5. Ask the question that tells you whether it landed. Let them show you on the screen.

• Every student needs Burger Lab open in a browser, with a mouse or a trackpad. It runs on a Chromebook. Nothing is installed.
• The lab shows inches and degrees Fahrenheit, or centimeters and Celsius. The two buttons under Size on the Shape bench switch it, and everything follows. This guide gives both where a number matters.
• Work is kept as the student goes when they are signed in. Without an account, nothing is saved; that is fine for a single lesson.
• Try lesson 1 yourself first. It takes twenty minutes and the surprises in it are the ones your students will have.
• Every rule, and the sauce path, can be shown as blocks instead of sentences or text: the Show as buttons over them open a Glassbox drawer. The lessons use the sentences, which read aloud well; blocks are there for students who already know them.

The lessons

Before the first lesson

• Open Burger Lab yourself. Press Grill in the tabs across the top. You should see Heat chips, three sliders (Side one, Side two, Rest off the heat), a Thermometer reading, a cut through the patty and a chart. That is the whole of lesson 1.
• Press Kitchen. You should see the kitchen floor from above with a grill, a fryer, a holding bin, a build station, a heat lamp and a window. That is lessons 2 and 3.
• Decide now whether your class will sign in. Signed in, each student keeps their burgers and their menu between lessons, and lesson 3 works best that way.

Lesson 1: The thermometer

One idea: heat takes time to reach the middle of a patty, so the only way to know it is done is to measure the middle. By the end every student has cooked the same patty two ways and can say why one came out under.

Lesson 1: Play first (0 to 8)

1. Say Build a burger. Any burger. You have eight minutes.
2. Students do Press Starters and pick one. Press Stack: add layers with the chips under Add on top, take them off with the small x, move them with the arrows. Press Shape and try the sliders. Press Look, tap a part of the burger, and give it a color.
3. On their screens A burger turning on a plate, and a line under it like 7 layers, 3.1 in tall, standing, patty 164 F, done. Some will have built a tower; the line will say leaning, and name the layer that is sliding.
4. If it goes wrong A burger has fallen over: it is lying on its side on the plate. That is the lab, not a bug. Ask what they stacked on what; wet layers slide.
5. Ask Nothing yet. Let them play.

Lesson 1: By the clock (8 to 20)

1. Say Press Starters and pick Classic, so we all have the same patty. Press Grill. Everyone: set Side one to 2:30, Side two to 2:30, Rest to 0:15. Medium heat. That is a recipe you could find anywhere: two and a half minutes a side.
2. Students do Press Grill. Drag Side one to 2:30, Side two to 2:30, Rest off the heat to 0:15. Leave Heat on Medium. Read the Thermometer.
3. On their screens The thermometer reads about 135 F (57 C) and the sentence under it says not there yet. Beef is done at 160 F (71 C). The cut through the patty is pink in the middle. The chart shows the middle climbing and stopping short of the dashed line marked done.
4. If it goes wrong A student reads done. Check Shape: their patty thickness is not 11/16 in (18 mm), or they picked the Smash burger, whose patty is thin. A thin patty is done by the clock; that is the point of the next step, so keep them.
5. Ask The recipe said two and a half minutes a side. Why is it not done? Wanted: the heat starts at the outside and has to travel to the middle, and the middle is the last place to get hot.

Lesson 1: By the thermometer (20 to 35)

1. Say Now cook it until the thermometer says done. Change only the times. Then make the patty thin on the Shape bench and do it again. Then thick.
2. Students do On Grill, move Side one and Side two up until the Thermometer reads 160 F (71 C) or more and the sentence says done. Write down the times. Press Shape, drag Patty thickness down to 3/8 in (10 mm), go back to Grill and find the times again. Then drag it to 1 3/16 in (30 mm) and try.
3. On their screens At 11/16 in (18 mm) the patty is done at about 4:00 a side with a short rest. At 3/8 in (10 mm) it is done in about half that, and at 4:00 a side the sentence says done, and past it: dry. At 1 3/16 in (30 mm) the sliders run out at 10:00 a side and the thermometer still reads under.
4. If it goes wrong The chart looks flat. Heat is on Low. Low will get there, slowly; let them find out, then put it back on Medium.
5. Ask The thick one never got done. What would you tell a cook who wants a thick patty? Wanted: give it longer and lower heat, or do not make it that thick for a fast kitchen. Then: press Starters, pick Garden burger, press Grill. Why does the plant patty want 165 F (74 C) and look pink when it is done? Wanted: the number comes from the package, and color is not how you tell.

Lesson 1: Show and ask (35 to 45)

1. Say Press Export and make A build card. Hold it up.
2. Students do Press Export, press Make it under A build card. The picture downloads, or goes to Files for students who are signed in.
3. On their screens A card with their burger pictured and pulled apart into its layers, each named, and the patty's line: Beef patty, 11/16 in, 164 F (73 C) in the middle, done.
4. If it goes wrong The card shows the patty under. Good: ask them to fix the times and make the card again. The card says what the thermometer said.
5. Ask Read the card at the bottom of the Grill bench together: You cannot tell by looking. Ask: what are the three numbers on it, and who uses each one? Wanted: 160 F is the USDA's number for ground beef at home, 165 F is what the plant-based package says, and 155 F for 17 seconds is the Food Code's rule for restaurants.

Lesson 2: The line

One idea: a kitchen is a queue. One cook does one thing at a time, in the order asked, and six grill spots are all there are. Rules written as sentences run the line, and the report says what they cost. By the end every student has run a nine-ticket rush and can read its report.

Lesson 2: By hand (0 to 10)

1. Say Press Kitchen. You are the cook. Tap an empty spot on the grill to put a patty on, tap it again to flip, again to bin it. Cook four patties, then tap the build station and the cook puts your burger together from the bin.
2. Students do Press Kitchen. Leave Practice selected. Press Start, on the floor. Tap grill spots: the first tap starts a patty, the second flips it, the third sends it to the holding bin. Watch the temperature on each patty. With a patty in the bin, tap the build station: the burger goes together on the board, layer by layer, and lands on the window shelf. Press Stop and report when four are binned.
3. On their screens The kitchen from above: the cook, in a white hat, walks between stations. Each patty shows a 1 or a 2 for the side that is down, its time on that side and its middle temperature. The cook's list is pinned to the back wall: what it is doing now, then what is waiting. The report lists each patty with its temperature and done, not there yet or dry, and says how many burgers were plated.
4. If it goes wrong Nothing happens when they tap. The cook is busy: read the cook's list on the back wall. Taps queue up; they are not lost. A tap on the build station with an empty bin says, on the floor, that the burger needs a patty in the bin.
5. Ask How many patties could you keep track of by hand? What did you forget? Wanted: the flips. A patty binned under is the usual result.

Lesson 2: Rules as sentences (10 to 25)

1. Say Now write the rules and let the cook follow them. Under Station rules, press By the clock. Read the six sentences out loud. Then Start.
2. Students do Under Station rules, press By the clock. Press Start, Fast. When the report comes, read it. Then press By the thermometer, Start again, and compare.
3. On their screens Six rule cards with blue numbers in them: when side one reaches 2:30, flip it; when side two reaches 2:30, bin it; and so on. By the clock, the report says 6 patties binned: 6 under. By the thermometer, 6 done, and the shift took longer.
4. If it goes wrong A rule card has an orange edge: a number in it is not one the lab can read. Blue numbers can be changed in place: click one, type, press Enter.
5. Ask Point at the two reports. Same patties, same grill. What changed? Wanted: the rule that bins looked at the thermometer instead of the clock, which is lesson 1 again, now as a rule.

Lesson 2: Build to the ticket (an option, 10 minutes)

Before any rules build the burgers for them, students can build them by hand. This is where the burger they stacked in lesson 1 meets the kitchen, and it is the clearest way to see what a ticket asks for. Use it with a quiet shift, before or in place of the first rush.

1. Say The kitchen will cook. You will build. When a ticket's food is ready the kitchen stops and hands you the ticket. Build what the ticket says, not what you usually make.
2. Students do Press Kitchen, Shift, Set up. Choose Quiet, 6 tickets. Under Who builds the burgers press I build them. Press Rules, then A plain line and By the thermometer. On the floor press Fast, then Start. When the pass opens, read the ticket, then press the pieces in the tray from the bottom bun up, and Send it out.
3. On their screens The pass over the kitchen: the ticket as printed on the left with the menu's recipe under it, the burger in 3D in the middle with a list of what has been built, and on the right a tray of buns, patties from the holding bin, toppings and sauces. After each one, a line on the floor: Ticket 2 went out right, or Ticket 2 went out wrong: left off the onion rings. The report ends with a line like 6 tickets built by hand, 5 right.
4. If it goes wrong Send it out stays grey. The burger is not closed: it needs a top bun. Or the patty button is grey: a patty comes out of the holding bin and none is left for this burger. Every ticket goes out wrong: they are building the menu's recipe and not reading the ticket. Say: read the ticket aloud first, then build.
5. Ask Which tickets did you get wrong, and what did they have in common? Wanted: the ones that changed the usual burger, no pickles, plant-based, an allergy. Then: what would a rule have to know to get those right every time? That question opens the rules that follow.

Lesson 2: The rush (25 to 40)

1. Say Customers. Press Shift. Press A plain line under Line rules and By the thermometer under Station rules. Press Start and watch the rail.
2. Students do Press Shift at the top of the panel, then Rules. Under Line rules press A plain line. Under Station rules press By the thermometer. Fast and Start are on the floor: press Fast, then Start. Watch: tickets land on the rail at the top with no onion and extra ketchup on them, customers queue at the counter and the drive-thru with a bar that shrinks, the cook starts patties for each ticket, builds and serves. Read the report.
3. On their screens Nine tickets. Most are served; some may walk out. The report says how many served, the average wait, the longest wait, whether any order was wrong, any patty under, the waste, the stars, and when the grill was full. Under it, a line per ticket.
4. If it goes wrong Most customers walk out. The burger on the menu has a thick patty (the Classic is 11/16 in). Say: six spots, four minutes a side; the grill cannot keep up, and the report's last line says so. Lesson 3 fixes it.
5. Ask Find a ticket with ALLERGY on it in the list. Was the order right? Wanted: yes, because A plain line has the rule when a ticket carries an allergy, leave out what carries it. Take that rule off with its x, run the same rush again, and find the line that says served sesame to a sesame allergy.

Lesson 2: Ask (40 to 45)

1. Ask Three questions, any order. The report said the grill was full from 0:52 to 8:34: what does that mean for the ninth customer? A flip asked for behind four starts comes late: why? If you could add one more thing to this kitchen, a cook, a grill spot or a basket, which, and how would you know it helped? Wanted for the last: run the same rush number and compare the reports.

Lesson 3: The rush to beat

One idea: the same rush with different rules gives a different report, and the only fair test is the same tickets. By the end every student has beaten their own score on one rush number, and can say which rule did it.

Lesson 3: A menu and a thin patty (0 to 10)

1. Say A fast kitchen runs thin patties. Build a burger with a thin patty, name your restaurant, and put two burgers on the menu.
2. Students do Press Starters, pick Smash burger. Press Menu, type a name under Your restaurant, press Put this burger on the menu. Press Starters, pick Classic, press Shape, drag Patty thickness to 3/8 in (10 mm), press Menu, Put this burger on the menu. Set a price for each if they like; the lab suggests one.
3. On their screens Two burgers on the menu with prices, and the restaurant's name at the top of the panel.
4. If it goes wrong Six at most, and a burger with the same name takes the old one's place. A student who put the same name on twice has one burger.
5. Ask Nothing yet.

Lesson 3: Beat it (10 to 35)

1. Say Press Kitchen, Shift. Run rush number 7 with A plain line and By the thermometer. That is your score to beat. Change one rule at a time and run the same rush again. The report will tell you whether you beat it.
2. Students do Press Kitchen, Shift. Check the panel says rush #7. Press Rules, then A plain line and By the thermometer. On the floor press Fast, then Start. The report opens when the shift ends: read it. Then change one thing: add serve the drive-thru first with its + chip; or press Cook ahead instead of A plain line; or change the number in when the bin holds fewer than 3 beef patties. Start again. Each report ends with a box: Beaten, Not this time, or Even, with both scores.
3. On their screens A box above the shift settings: Rush #7: The Patty Wagon served 8 of 9 at 3.6 stars. Run it with your rules and beat it. After each run, the report's verdict box.
4. If it goes wrong Every run says Even. They changed something that did not reach this rush (fries, oil) or the change made no difference to these tickets. Say: that is a result too; write it down and change something that touches the grill or the bin.
5. Ask Which single change made the biggest difference, and what did it cost? Wanted: cooking ahead cuts the wait and raises the waste; drive-thru first helps the lane and hurts the counter; the report has the numbers for both.

Lesson 3: Share and ask (35 to 45)

1. Say Signed-in students: press Export and make The menu board, then share the project. Anyone who opens it can press Run the rush and see your shift run again, and a copy of it carries your rush to beat.
2. Students do Press Export, press Make it under The menu board. Share the project from the platform's Share button; the share page shows the burger, and Run the rush replays the shift with the report beside it.
3. On their screens The menu board with the restaurant's name over MENU, each burger pictured with its price and allergens.
4. Ask Why does a friend running your rush get the same tickets? Wanted: the rush number is a seed; the same number makes the same customers in the same order, so the only thing that differs is the rules. That is what makes the comparison fair.

Lesson 3: Robots on the crew (an extension)

For a class that finishes early, or a fifth session. The kitchen can rent robots, one to a station: a grill arm, a fry arm and an assembly line. Each runs the rules the student already has, on its own list. The idea is parallel work, and the surprise is that more hands often do not help: the slowest step sets the pace.

1. Say Your cook does one thing at a time. Rent it a robot and see what changes. Before you press Start, say which robot you think will help most, and why.
2. Students do Press Kitchen, Shift, Set up. Under The crew press Grill arm. Press Rules and read the labels on the rules: each now says whose program it is in, the grill arm or the cook. Run the same rush as before. Read the last lines of the report. Then try the fry arm alone, the assembly line alone, and all three.
3. On their screens An orange carriage on a rail behind the grill, with an arm that reaches down to the patty it is working on and a small label for what it is doing. With the assembly line, a belt from the build station to the window and wrapped burgers riding it. The report adds the robots' rent to the money line and ends with a line like: The cook was busy 38% of the time, the grill arm 28%.
4. If it goes wrong The robot made no difference, or the profit went down. Nothing is wrong: that is the result. Say: read how busy the cook was before you rented it. If the cook had time to spare, hands were never the problem.
5. Ask Which robot was worth its rent on this rush, and how do you know? Wanted: the report's busy numbers. A robot that was busy took work off a cook who had none to spare; a robot that sat idle cost money and changed nothing, because the grill's six spots or the patty's cooking time was the limit.

Lesson 4: The program (optional)

For students who have met JavaScript, or are about to. One idea: the rules are a function. Once a kitchen second the kitchen hands it a picture of itself and it returns what the cook should do next. By the end every student has read the starter program, changed one number, run it, and saved it as a file.

Lesson 4: Read it (0 to 15)

1. Say Press Kitchen, Shift. Under Rules as, press Code. Read the program from the top. Do not change anything yet.
2. Students do Press Kitchen, Shift, then Code under Rules as. Read the comment at the top, then the function next(kitchen). Find the loop over the grill, the two if lines in it, the loop over the tickets, and the line that returns todo.
3. On their screens A box of about forty lines of JavaScript starting with a comment that names every field the function is handed and every action it can return. Under the box: It reads. Press Start to run it.
4. If it goes wrong The line under the box is orange: the program does not read. They typed in it. Press Start from the plain line to get the starter back.
5. Ask Point at g.side === 1 && g.sideTime >= 120. Which sentence rule is this? Wanted: when side one reaches 2:00, flip it. Point at g.peak >= done(g.kind). Which? Wanted: when the middle reaches 160 F, bin it, and done(g.kind) is 165 F for a plant patty.

Lesson 4: Change one thing and run (15 to 35)

1. Say Change one number and press Start. Then another. Beat your sentence score from lesson 3 with code.
2. Students do Change 120 to 90 in the flip line. Press Start, Fast. Read the report and its verdict box. Then try the fries: 180 to 150 in the lift line. Then, for the brave, add a line before the tickets loop: if (kitchen.bin.length < 2) and a start, the way the loop over tickets does it.
3. On their screens The floor runs as before; the note at the top right says your scheduler running. If the program throws, it stops for the run and the report says Your scheduler stopped at 2:14 and the reason.
4. If it goes wrong The scheduler stopped: a typo. Read the reason under the report; it is the browser's own message. Fix it and Start again.
5. Ask Why does the function return a list instead of doing things itself? Wanted: the cook does one thing at a time, in order; the list is the queue, and the kitchen decides when each thing happens.

Lesson 4: Take it with you (35 to 45)

1. Say Press Export and save Your scheduler as a file. That file runs outside the lab, in Node, against the same kitchen.
2. Students do Press Export, press Make it under Your scheduler as a file. Open the file in any editor and read the first four lines: they say how to run it with run-scheduler.cjs from the Burger Lab repository.
3. On their screens A .js file with their function and module.exports at the bottom.
4. Ask What would you need to run this on a real kitchen? Wanted: a real picture of the kitchen instead of the lab's, and real actions; the function would not change. That is what a kitchen display system does.

Lesson 4: The reader (a second session)

A second program, for a second session: the ticket reader. The kitchen reads every ticket right; a student can switch in a program of their own that reads the printed ticket into what to make, and then whatever it misses goes out wrong.

1. Say Press Kitchen, Shift. Under The ticket reader, press My reader reads them. Read the comment at the top: that is what a ticket looks like, and that is what the program has to hand back. The starter reads only the names. Press Try it on 40 tickets.
2. Students do Press My reader reads them, then Try it on 40 tickets. Read the score and what it missed. Add one line that reads the FRIES line, press Try it on 40 tickets again. Then the ALLERGY line. Then the words after the first comma.
3. On their screens A score like 11 of 40 tickets read right, and under it Missed: the fries line (24), a modifier like no pickles (14), the allergy line (8). Each line they add raises the score. A reader that reads every line scores 40 of 40.
4. If it goes wrong The score does not move. They are reading the wrong text: the ticket says FRIES regular on its own line, in capitals, and the mods come after a comma and a space. Say: print one ticket on paper and read it with a finger.
5. Ask Press Start with the reader switched in and read the report. Which orders went out wrong, and what did the reader miss on each? Wanted: the report names it per ticket: no fries on an order with fries, missed no pickles, missed the allergy. Text is data; a program that reads half of it serves half the order.

Where to go next

• Hat Lab and Shirt Lab share the bench with Burger Lab: the same Stack, Look, Mark and Export benches, for a game asset instead of a lunch.
• Help Desk is a different queue: tickets with people behind them, and rules for who gets served first.
• Drink Lab is a design bench for the drink that goes with the burger.
• The Pseudocode Tracer, for students headed to AP Computer Science Principles, traces programs like the one in lesson 4 line by line.

More help

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