Your first week
Everything below takes five minutes on Monday and about three minutes a day after that. You do not need to read it all now. Do step one, and come back on Friday for the last part.
Before the lesson
Print the code sheet
In your dashboard, open the class and press Print code sheet. It carries the six-character code in large type and a QR code. One on the wall, one on your desk. Students who miss the lesson can still join from the wall.
Put the board on the projector before they come in
Open divisibledash.com/class in a browser and type the code. No login is needed and the board is safe to project, because it shows picked names such as SwiftFalcon42 rather than real ones.
Leaving it up as they walk in does most of the selling for you. An empty board that fills up during the lesson is a better introduction than anything you can say.
Decide the tier before the lesson, not during it. Beginner is 2, 3, 5 and 10. Intermediate adds 4, 6, 8 and 9. Advanced is all of them including 7. Pick the one your class can get most of right, not the one that matches their year group. They can move up in week two and it feels like progress; moving down does not.
The first lesson, five minutes
Do not explain the rules first. Let them play one run and fail at it, then explain. The failure is what makes the explanation land.
Get them in
Phones or laptops out, app open, JOIN CLASS, type the code. That is the whole join. There is nothing to sign up for and no password to set.
"Tap JOIN CLASS and type the six characters on the board. Do not put your name anywhere, there is nowhere to put it. The game gives you one."
One run each, no instructions
Let them work out the swipe themselves. It takes most students about fifteen seconds and they remember it better for having found it.
"Press the Daily Challenge. Read the rule at the top. Swipe the number right if it follows the rule, left if it does not. Go."
Look at the board together
Turn round and look at the projector. The board is live, so their names are already on it. This is the moment the class decides whether it cares, and it usually does.
"That is everyone in this room. Tomorrow's numbers are exactly the same for every player in the world, so there is no hiding and no grinding. One run each, every day."
Teach one rule, the one they just lost on
Ask who got caught by a number they thought was divisible and was not. It is almost always 4 or 8, and it is almost always because they checked one digit fewer than the rule asks for.
"4 is the last two digits. 8 is the last three. Not the last one. 34 ends in an even 4 and is not a multiple of 4, and that is the trap you just walked into."
The rules from 2 to 12, with worked examples, are on the rules page if you want them on the board.
The rest of the week
Three minutes a day. The Daily Challenge is one run, which is what makes this sustainable: there is no version of it that eats a lesson.
The lesson above. Board up, everyone joins, one run, teach one rule.
Board up as a starter. One run. Name yesterday's weakest rule and teach it for two minutes.
Say nothing. See who plays anyway. That number is the honest one.
Open the insights. Put the class accuracy bars on the board and let them see the worst rule.
Look back at Monday. Same board, five days on. Then decide whether to move up a tier.
Do not make it a homework task with a mark attached. The Daily Challenge works because it is short, optional and slightly competitive. Attaching a grade to it turns a thing they do into a thing they have to do, and the play rate falls the week you try it. The board is the incentive, and it is enough.
What to look at on Friday
The leaderboard is what students care about. The insights are what you should care about, and they are the reason the class board is worth having at all.
The weakest rule, for the class
Accuracy on each rule from 2 to 12 across everyone. This is the single most useful number on the dashboard, because it tells you what to teach on Monday rather than what to praise on Friday.
The weakest rule, per student
The same breakdown for one student, with their weakest rule named. Useful in a conversation with the student who is quietly guessing on 7 and quick on everything else.
Accuracy by number size
Whether the rule holds up when the numbers get longer. A student solid on two digits and lost on four has not learned the rule, they have learned the two-digit cases.
Who has actually played
Runs per student. The quiet finding in most first weeks is that a third of the class played every day, a third played twice, and a third never opened it. Worth knowing before you draw any conclusion from the scores.
Everything on screen exports to CSV, so the department can keep its own record without anyone retyping anything.
When something goes wrong
The honest list, including the things that are genuinely awkward.
A student says the code does not work
Nearly always a typing problem. A code never contains 0, 1, I or O, so a character that looks like one of those is something else, such as a D, a Q, a J or an L. Check they are on JOIN CLASS rather than a friend code box.
If it still fails, the class may be archived. Check it in your dashboard.
A student has vanished off the board
If they reinstalled the app or changed device, their class membership can drop. Give them the code again and they rejoin in ten seconds, keeping their old scores. It is worth leaving the code sheet on the wall all term for exactly this reason.
Students are not allowed phones in school
The most common case, and it does not stop the class board working. Most classes play at home, which suits a one-run-a-day game, and the board still fills.
For the room itself, the board opens in any browser at divisibledash.com/class with the code alone, so you can project it without a single device in students' hands.
Two students have the same picked name
Picked names carry a number, so a genuine collision is rare. If you need to know who is who, add an optional roster in your dashboard: first name and last initial, visible only to you, never on the projected board. It is the only place a real name exists anywhere in the system.
The class has lost interest by week three
Usually one of two things. Either the tier is too easy, in which case move up and the board resets into a real contest again, or the board stopped going on the projector. The board is the whole mechanism. A class board nobody sees is just a database.
Something else, or something broken
Email support@divisibledash.com. It reaches the person who wrote the code, and a report that something is broken is more useful to me than one that says it is fine.
One thing to do next
If the first week works, tell one colleague and send them divisibledash.com/schools. Each teacher makes their own classes, there is nothing central to set up, and a second class costs exactly what the first one did. For a department meeting, there are six slides to project.
If it did not work, I would rather know why than not. support@divisibledash.com.