A math board with an AI tutor

Every answer has a story.

Students solve by hand. Kribu's tutor reads their work and helps right on the page, and you see every step.

How many terms inside the parentheses does the 3 multiply?

You corrected the constant term of the expansion: −3.

What operation could you do to both sides to reduce the number of x terms or constants?

What did you do to each side between these two lines?

“Add” doesn't describe the step you wrote: the x term on the right shouldn't be added on the left; you need to subtract 4x from both sides.

What's left after that subtraction?

How many terms inside the parentheses does the 3 multiply?

What operation could you do to both sides to reduce the number of x terms or constants?

What did you do to each side between these two lines?

What's left after that subtraction?

With a tutor

It spots the slip.

Nora multiplied the 2x by 3, but not the −1.

It asks. It doesn't tell.

It underlines her 1, highlights the equation and asks one question, out loud.It underlines her 1 and asks, out loud.

The fix is hers.

She erases the 1 and writes a 3. The tutor credits it and moves on.She erases the 1 and writes a 3.

Another slip.

This time the 4x crossed the equals sign unchanged. First, a question.The 4x crossed unchanged. First, a question.

The help steps up.

She answers “add.” So it points the way: it writes the move on her page and leaves the working to her.It writes the move. She does the rest.

A question
A pointer
A worked step
An explanation

Help goes up one rung at a time, only as far as needed. Nora never needed more than a pointer.

With a tutor

It spots the slip.

Nora multiplied the 2x by 3, but not the −1.

It asks. It doesn't tell.

It underlines her 1, highlights the equation and asks one question, out loud.It underlines her 1 and asks, out loud.

The fix is hers.

She erases the 1 and writes a 3. The tutor credits it and moves on.She erases the 1 and writes a 3.

Another slip.

This time the 4x crossed the equals sign unchanged. First, a question.The 4x crossed unchanged. First, a question.

The help steps up.

She answers “add.” So it points the way: it writes the move on her page and leaves the working to her.It writes the move. She does the rest.

A question
A pointer
A worked step
An explanation

Help goes up one rung at a time, only as far as needed. Nora never needed more than a pointer.

How many terms inside the parentheses does the 3 multiply?

You corrected the constant term of the expansion: −3.

What operation could you do to both sides to reduce the number of x terms or constants?

What did you do to each side between these two lines?

“Add” doesn't describe the step you wrote: the x term on the right shouldn't be added on the left; you need to subtract 4x from both sides.

What's left after that subtraction?

How many terms inside the parentheses does the 3 multiply?

What operation could you do to both sides to reduce the number of x terms or constants?

What did you do to each side between these two lines?

What's left after that subtraction?

That was one student. You have thirty.

Live classroom

Every board in the room, live.

Each student works with their own tutor. You see every page at once.

Whoever needs you comes first.

With the reason, so you know what to say before you walk over.

SessionsAlgebra 9B27 working · 3 need you · 3 solvedLive

Needs you3

3(2x - 1) = 4x + 5

Needs you

NNoraAlgebra 9B · 1 min

A term crossed the equals sign without changing, 2 turns in a row

3(2x - 1) = 4x + 5

Needs you

BBielAlgebra 9B · 1 min

Sign lost when expanding, 2 turns in a row

3(2x - 1) = 4x + 5

Needs you

NNilAlgebra 9B · 1 min

The 3 reaches only the first term, 2 turns in a row

Working27

3(2x - 1) = 4x + 5

Working

AArnauAlgebra 9B · 1 min

3(2x - 1) = 4x + 5

Working

JJanAlgebra 9B · 2 min

3(2x - 1) = 4x + 5

Solved

PPauAlgebra 9B · 2 min

3(2x - 1) = 4x + 5

Working

MMartíAlgebra 9B · 2 min

3(2x - 1) = 4x + 5

Working

AAinaAlgebra 9B · 1 min

3(2x - 1) = 4x + 5

Solved

JJúliaAlgebra 9B · 2 min

3(2x - 1) = 4x + 5

Working

PPolAlgebra 9B · 1 min

3(2x - 1) = 4x + 5

Solved

EEmmaAlgebra 9B · 3 min

After class

Replay any attempt.

Every stroke and every tutor turn. Scrub back to any moment.

Evidence, not a grade.

The report names each misconception, frames the line where it started and suggests what to do next class.

SessionsNNora · Solve 3(2x − 1) = 4x + 57 tutor turnsSolvedFull replayIndividualGroup

Solved in 7 turnsSolved

Length2:27Misconceptions2Errors0Turns with help3 of 7

In the recording now

Turn 1 · 0:08On a sticking point A question

Misconceptions2

Turn 1, as sent1The 3 reaches only the first termFixed at turn 2The board reads 6x - 1 = 4x + 5: the 3 was applied to 2x but not to -1.Turn 1·help up to a question
Turn 3, as sent2A term crossed the equals sign without changingFixed at turn 5The unchanged second line reads 6x + 4x = 5 - 3; the 4x moved left without changing sign.Turns 3–4·help up to a pointer

Teacher recommendations

Quick check on “The 3 reaches only the first term”Fixed after a question (turn 1).In class: A short warm-up question next lesson is enough to confirm it stuck.
Revisit “A term crossed the equals sign without changing”Turns 3–4: fixed only after a pointer.In class: Model it once with a visual, then have the student explain the step aloud on a new example of “Terms collected toward ax = b”.
Light help was enoughKribu's help never went past a pointer (3 of 7 turns had some).In class: Next time, let the student try the first steps with fewer prompts.
Most of the work went into “Terms collected toward ax = b”3 of 7 turns were spent before reaching it.In class: Give that step extra practice before moving on to the rest of the solution.

Writing

Talking

Tutor

1234567

0:001:002:00

0:08

2:271×

On my own

No tutor.Just their thinking.

A ruled notebook and a voice recorder, with no AI. They write, and explain out loud as they go.A notebook and a voice recorder. No AI.

Think aloudFinish attempt

Your question

A theatre has 8 rows with 12 seats in each row. 5 seats are broken. How many seats can people sit in?

Record voiceStop recordingNew recording0:5310 min max

Later, you hear it.

Replay their ink and their voice together, stroke by stroke.Their ink and their voice, together.

Theatre seatsLeo

Your question

A theatre has 8 rows with 12 seats in each row. 5 seats are broken. How many seats can people sit in?

1:03 / 1:221×

Tests

One exercise at a time.

Share a test as one link. Each exercise opens with the live tutor, or in the notebook where they work on their own.One link, one exercise at a time.

Every result, with its recording.

Each student's run lands in Exams as they finish, every exercise ready to replay.Every run in Exams, ready to replay.

−2x+12=−4(3−4x)

Unit 3 check1/32/33/3

CompletedOct 9, 2026

Unit 3 check

NNora

3 exercises submitted

2 correct1 ungraded

Results savedView results

More than right or wrong.

In tests and in practice, Kribu keeps how every answer was reached.Kribu keeps how every answer was reached.

1. Multi-step linear equationCorrectView recording

Every strokeEvery stroke

What they saidWhat they said

Every tutor turnTutor turns1234

The help it tookHelp it tookA question

Misconceptions, found and fixedMisconceptionsSign lost when expandingFixed at turn 2

0:001:002:003:003:12

Coming soon

What it all adds up to.

Soon, Assessment will bring tests and practice together to predict how each student will do in their next test.Soon, Assessment will predict the next test.

NNoraAlgebra 9B · 6 sessions · last Wed Oct 7

OverviewWorkDifficulties

Predicted resultsComing soonEstimate

What Nora would likely score in the next tests, from the sessions on each test's competences. It will be calibrated against real test results.

Unit 3 testClass test · Fri Oct 23On track6.8/ 10+0.6 in 4 weeksLikely 5.9–7.6Pass at 5Needs less help each week (a question, down from a pointer)Still moves a term across = without changing its sign (2 of the last 5)Covers 4 of 5 competences · medium confidence

First term evaluationSchool evaluation · Wed Dec 16Borderline5.6/ 10+0.3 in 4 weeksLikely 4.7–6.6Pass at 5Both equations correct in the Unit 3 checkInequalities not practised yetCovers 5 of 9 competences · low confidence

Your activities

From the library, or your own.

Use activities from the Innovamat library or create your own, then assign them to a class.

Exercise Library New Exercise

Search by title, statement or topic All exercises Filters

x Solve 3(2x − 1) = 4x + 5 linear equation · Grade 8 3(2x−1)=4x+5
+ Theatre seats arithmetic · Any grade A theatre has 8 rows with 12 seats in each row. 5 seats are broken. How many seats can people sit in?

Nora · 2:27 · 7 tutor turns · x = 4

Every answer has a story. Now you can read it.

Solve a lesson with the tutor, then see the report a teacher gets.

Try Kribu Sign in

Questions

Does the tutor give away answers?

No. It starts with a question and gives more only while a student stays stuck: a pointer, then a worked step, then an explanation.

What do I see as a teacher?

Every live board in your class, with the students who need you first and why. After class, replay any attempt, read a report on each student's misconceptions with the moment they appeared, and compare every attempt at the same exercise.

Can I use my own activities?

Yes. Use activities from the Innovamat library or create your own, then assign them to a class.

Can I run a test in Kribu?

Yes. Publish a test in Exams and share its link. Students work through it one exercise at a time, each with the live tutor or in the notebook, and you see every finished run with its results and recordings.

Will Kribu predict how students will do?

Coming soon. Assessment will bring each student's tests and practice together to estimate what they would likely score in their next tests, and show what moves the estimate up or down.

Which languages does it speak?

English, Spanish and Catalan. The tutor speaks to each student in their language.