One blank sheet of paper with four writing tools pointing at it: a fountain pen, a pencil, a felt marker and a paintbrushHow we make a book

A book, its study guide, its question bank

A student learns a subject, makes it stay, and tests it. Each title has a volume for each: the book to learn from, the study guide to keep it, the question bank to test it.

Every page below is a real page from Class 10 Mathematics. The book is in a draft edition. The study guide and the question bank are assembled and reviewed, and not yet on sale.

The book · to learn

Written for its reader, to read alone

A learner should be able to learn the subject from the page, with no tutor beside them. So each idea is written for the reader it is meant for: their class, the English they read, the exam they sit.

How it is madeEach idea is held once, as one checked source. QUILL, our writing tool, writes it out for each reader. The idea stays fixed; only the voice and the level change.

One idea, four voices

The idea stays the same. The voice changes.

The four passages below teach the same idea. Each is written for a different reader, so each sounds like a different person.

The idea, word for word

A generative model learns a statistical distribution over training data; at generation time it samples one plausible output from that distribution given a prompt. It does not retrieve from a database; every output is constructed fresh by sampling.

the claimlocked
The Teacher
The CSAT Coach
The Adult-Remediation Voice
Priya (the Wondering Voice)
The claim — locked, unchanged
The Teacher
The CSAT Coach
The Adult-Remediation Voice
Priya (the Wondering Voice)
One claim, unchanged at the hub. Four spokes out — one locked, three composed to make the contrast visible.
A page from the Class 9 Generative AI chapter’s draft print layout (not yet released): the clerk-in-a-record-room and tea-stall-man passages, the same words the Teacher card quotes.
The draft page: the Teacher’s passage, word for word.

This is the book page the first passage comes from: Chapter 14 of the Class 9 AI book, in its draft layout. The passage is quoted from it word for word.

The TeacherFrom the book

Someone who worked it out and is showing you how: a few steps ahead of you, not lecturing at a board.

Picture the machine that writes your poem as a clerk in a record room. Somewhere inside, in a labelled file, your poem is lying finished, and the clerk’s whole job is to find it. Most of us carry some version of this picture — where else would the poem come from?

Test it. Ask for the poem twice. Two different poems come back. A clerk pulling a finished page from a file would bring the same page both times. So there is no file.

Then what is inside? Think of the man at the tea stall you cross every day after school. Thirty years at that counter, and every kind of talk has passed in front of him — results day, match day, bandh day. Has he memorised even one of those conversations? Not one. But say two sentences to him and he can tell where the third is going. Not because he has heard your third sentence before — because thirty years gave him a feel for what follows what.

A generative model holds exactly that kind of feel, learned from everything it trained on — not stored answers, but a statistical sense of what tends to follow what. Give it a prompt, and it draws one plausible reply from that sense, built fresh, word by word. Nothing is fetched from storage — every output is built at the moment you ask for it.

Quoted in full, word for word, from a Class 9 chapter.
The CSAT CoachWritten for this page

Has read every past paper. Names the trap out loud, with no warm-up, and talks to you as the candidate in the hall.

“Generative AI retrieves its answer from a large database.” Read that option again. It sounds right. It borrows the syllabus’s own words, and it is the picture most candidates carry into the hall — which is exactly why it is on the paper.

It is wrong, and the examiner knows how many of you will tick it. A generative model stores no answers. It learns a distribution — a statistical sense of what tends to follow what — and at generation it draws one plausible output from it.

The tell is one word: retrieves. Retrieval means the answer existed before the question was asked. Nothing existed here until you prompted it. So the rule is flat, and it will hold across every phrasing they try: when an option says the machine found the answer, strike it. The machine made the answer.

A draft page from the UPSC reading-comprehension chapter’s print layout, not yet released. A boxed instruction asks students to tag all four verbs on the intensity axis, where the two extreme verbs are meant to be obvious. Four option-verbs are tagged extreme-active, extreme-active, extreme-passive and moderate-procedural, with a numbered five-step method below.
A draft page from the CSAT Coach’s UPSC chapter. Not on sale yet.
This voice is already used in a live UPSC reading chapter.
The Adult-Remediation VoiceWritten for this page

Speaks to an adult the system let down, not to a slow learner. Starts from what the reader already does well.

If you have kept away from these tools assuming there is a technical layer you missed, there isn’t one here. The picture you are probably carrying — the machine looks the answer up somewhere — is not a gap in your education. It is where nearly everyone starts, and it is plainly wrong.

Here is what actually happens. The model has read an enormous amount of text and kept none of it word for word. What it kept is a feel for how such writing tends to go — the same way you can tell a letter from your bank apart from a letter from a friend, instantly, without being able to name the rule you used.

Ask it something and it builds a reply out of that feel, one likely word after another. Nothing was stored. Nothing was found. It was made, while you waited.

This voice is already used in a full adult chapter on fractions.
Priya (the Wondering Voice)Written for this page

A classmate, not a teacher. She says her first, wrong guess out loud, then changes her mind in the open.

I asked it for a poem about the monsoon, and it wrote me one. Then I asked again, and the poem was different.

That puzzled me for a while. If it had a poem kept somewhere, surely the same one would come back both times? So where was the first poem, before I asked for it?

I think the answer is: nowhere. It wasn’t anywhere at all. The machine hasn’t kept poems — it has kept a sense of how poems tend to go, the way I can hear that a line has one sound too many without stopping to count. When I ask, it makes one, one likely word after the next.

Which means the poem I got is not a poem it had. It is a poem it did. I am still deciding how I feel about that.

No chapter in this voice yet. It is planned for the English books for Classes 6 to 8.

Only the first passage is quoted from a book. The others were written for this page, on the same idea, to show the difference. The note under each says where that voice is used today.

Page v of the Class 10 Mathematics book, How to use this book. It shows a worked example with a reason beside each step, a First Try, Second Look panel, the short notes, and a practice set with its answers under it.
Page v of the book: four devices cut from the chapters, with what to do with each.
The book · to learn

Every step carries its reason

In a worked example, each step has its reason written beside it, so a student can check the thinking, not just the answer. Short notes sit under the text they belong to: the rule, the key idea, a quick try, a common slip.

How it is madeEach idea is written with its reason attached, so wherever the rule is printed, the reason is printed beside it.

The book · to learn

No gimmicks, and no talking down

The book never flatters, pads or tries to be clever. A younger reader gets simpler words, never less respect, and the idea itself does not shrink.

How it is madeReadability is scored with the subject’s own words masked, so a chapter is never marked hard for the words it has to teach. Every example is judged from an Indian student’s seat: written for that reader, not translated for them.

A screenshot of the live Manthika app, Section 2 of the Class 9 Generative AI chapter: the training-to-sampling diagram. Training data becomes a learned distribution, and the model draws one output from it for each prompt. The diagram’s own caption states the base model holds no answer database of its own, so every output is a fresh draw from the distribution, not a retrieval.
The same idea in the live app, written at the Class 9 reader’s level.
One voice, every class level

Simpler words, never less respect

Keep the Teacher’s voice and change only the class. The words get simpler for a younger reader and more exact for an older one. The idea underneath does not move.

g6-7
g9
g11-12
simpler wordingmore technicalsame claim — unchanged
The same claim beneath every reading level — only the wording slides from simple to technical.
Class 6 to 7Written for this page

Ask it for a poem. It does not go and find one, because there is no poem to find — not in a drawer, not in a list, nowhere. What it has is a feel for how poems go. So it builds you one, word by word, while you wait. Ask twice and you get two poems. Made things vary.

Class 9From the book

A generative model learns exactly that kind of feel, built from everything it trained on — not stored answers, but a statistical sense of what tends to follow what. Give it a prompt, and it draws one plausible reply from that sense, built fresh, word by word. Nothing is fetched from storage — every output is built at the moment you ask for it.

Class 11 to 12Written for this page

What the model holds is a learned distribution over its training corpus — not an index into it. Generation is a sampling operation: given a prompt, it draws one plausible completion. The output is constructed, and the construction is stochastic. That is the whole reason one prompt admits many equally valid answers, and why plausibility is not truth.

The book · to learn

Every wrong answer is a real mistake

Each wrong option is a mistake students actually make, and the book says why that thinking went wrong. The question bank’s key gives a reason for every answer.

How we check every question
The top of the question bank’s answer key, page 14. Each answer letter is followed by a one-line reason, such as why 1 is not a prime.
The question bank’s key: a reason beside every answer.
A First Try, Second Look panel from page v of the book. A student’s wrong working for the LCM of 9, 15 and 21 is struck through, then corrected from the primes.
A real wrong turn, struck through, then put right.
The book · to learn

Figures that answer the question

Cover the caption and the figure still answers the exam question. No page is a wall of text.

What every book on the shelf meets
Page 342 of the book, from the Circles chapter. Two right triangles share a hypotenuse of 13 and a side of 5, with the Back, Rule and Key notes above and a Check yourself below.
Page 342: the figure carries the rule, with or without its caption.
The book · to learn

Nothing above the class, nothing assumed

The book teaches nothing from a higher class. Where a chapter leans on Class 9, it checks that first, on a Before you start page, instead of assuming it. A later chapter never quietly contradicts an earlier one.

How it is madeEvery chapter is checked against its class’s syllabus, and each new chapter is checked against the ones before it.

The Before you start band from page 4 of the book. Four Class 9 checks are drawn as one picture, with the primes of 36, of 60 and 40, of 4 and 6, and of 90 shown as tokens.
Page 4: four Class 9 checks, as one picture.
The book · to learn

Every fact and number, checked twice

Two separate readers go through every passage. The answers to each practice set are printed under it, and the full working is online.

How a chapter is checked
Page 34 of the book, Exercise 1.1. The first question is worked in full with a reason beside each step, and every answer in the set is printed under it.
Page 34: the answers sit under the set, with the full working online.
The book · to learn

The cover is a map of the book

Each chapter is a station on the cover’s route, in order, so you can see the whole year before you open the book.

See the covers on the shelf
The whole cover of Class 10 Mathematics, back, spine and face. The face is a route map with each chapter a station, and the back lists what is inside.
The whole cover: each chapter is a station, in order.
The study guide · to make it stay

The study guide makes it stay

A second, shorter book for revising. Its notes fight back: the question is printed and the notes are left to the student. On a fold sheet the student says each idea aloud from its title, and an error log names the chapter’s traps.

How it is madeThe guide is built from the same checked source as the book. It holds what a student does to revise, and leaves the explaining to the book.

Assembled and reviewed. Not on sale yet.

Study guide page 4, Notes that fight back. The question In how many ways does a composite number factor into primes? sits in the cue column, and the note lines beside it are blank.
Notes that fight back: the question is printed, the notes are the student’s.
Study guide page 11, Say it from the title. A fold sheet lists each idea’s title on the left and its one-line statement on the right.
Fold the sheet, read the title, say the idea aloud, then check.
Study guide page 14, the Error log. The chapter’s named traps are listed, then a table where the student writes each wrong answer and ticks the trap that caught them.
The error log: each wrong answer, matched to the trap behind it.
The question bank · to test it

The question bank, under exam conditions

Each chapter opens with a sheet of the facts a student may look at, then a worksheet, then its answer key on a page of its own. Spaced worksheets follow, and sample papers close the volume.

How it is madeThe questions come from the same bank the app grades, and each wrong option is a mistake a real student makes.

Assembled and reviewed. Not on sale yet.

Question bank page 3, the first page of the Real Numbers worksheet: multiple-choice questions, each with four options and no answers on the page.
The chapter’s worksheet: questions only, the key comes later.
Question bank page 14, the answer key. Each answer letter is followed by a one-line reason.
The key, on its own page: every answer with its reason.
After the book reaches you

Report a mistake, see it fixed

Every page of the book carries the address manthika.com/fix at its foot. A mistake we accept there is corrected in the book’s source, so the fix lands in the next build of the web page and the printed book.

How it is madeWe promise where a fix goes, not how fast it gets there.

The Report a mistake page on manthika.com, where a reader says which book and page, and what is wrong.
The page every page of the book points to.
Counted

Counted against the textbook

We picked three chapters in each of our three books and counted the same things in the same chapters of the NCERT textbook and four widely used guides. Every number here is a count, not an estimate. The guides were counted, not named. One count goes against us, and we show it too.

NCERTThis bookClass 10 · Quadratic Equations1.492.50Class 10 · Triangles2.691.69Class 10 · Statistics1.682.89Class 11 · Sets1.442.46Class 11 · Straight Lines0.241.81Class 11 · Limits and Derivatives0.221.93Class 12 · Matrices2.202.45Class 12 · Integrals0.762.40Class 12 · Probability0.993.01
Why-language, per 1,000 words
NCERTThis bookClass 10 · Quadratic Equations1.492.50Class 10 · Triangles2.691.69Class 10 · Statistics1.682.89Class 11 · Sets1.442.46Class 11 · Straight Lines0.241.81Class 11 · Limits and Derivatives0.221.93Class 12 · Matrices2.202.45Class 12 · Integrals0.762.40Class 12 · Probability0.993.01
Why-language, per 1,000 words
What was countedNCERTThis bookFour guides
Why-language, per 1,000 wordsClass 10 · 1.49, 2.69, 1.68Class 11 · 1.44, 0.24, 0.22Class 12 · 2.20, 0.76, 0.99Class 10 · 2.50, 1.69, 2.89Class 11 · 2.46, 1.81, 1.93Class 12 · 2.45, 2.40, 3.01Class 10 · not countedClass 11 · 0.00–0.89Class 12 · 0.00–0.94

This book uses more why-language than NCERT in 8 of 9 chapters, by 1.1 to 9 times. NCERT is higher in Class 10 Triangles, where its count comes from the (Why?) prompts inside its proofs. Every guide counts at or below NCERT in every chapter.

Mistakes named and put rightClass 10 · 1, 2, 0Class 11 · notes state the fact, none names a wrong beliefClass 12 · notes state the fact, none names a wrong beliefClass 10 · 8, 15, 6Class 11 · 12, 12, 10Class 12 · 11, 13, 7No guide names a wrong belief, in any class.

This book runs 6 to 15 boxes a chapter that name a mistake a student makes, work it wrong, then show it right. No NCERT chapter, and no guide chapter we counted, names a wrong belief; their notes state the correct fact instead.

Worked examplesClass 10 · 9, 8, 8Class 11 · 25, 16, 22Class 12 · 25, 42, 24Class 10 · 6, 6, 6Class 11 · 8, 9, 9Class 12 · 5, 8, 4Class 10 · not countedClass 11 · 44–113Class 12 · 30–64 (first-span counts)

NCERT runs more worked examples than this book in 8 of 9 chapters, and the guides run 2 to 10 times our count. Ours are about twice as long, and a worked solution sits behind every practice problem, shown in the row below.

Practice problems, solvedClass 10 · 265Class 11 · 623Class 12 · 952Class 10 · 594Class 11 · 740Class 12 · 1,010Final answers printed after each exercise; one guide adds hints for selected problems.

This book prints 594, 740 and 1,010 practice problems across the three classes, every one with a worked solution and the reason beside each step. NCERT and the guides print only the final answer; one guide adds hints for some problems.

NCERTThis bookClass 10265594Class 11623740Class 129521,010
Practice problems, solved
NCERTThis bookClass 10265594Class 11623740Class 129521,010
Practice problems, solved

What we found against ourselves

On the results we checked, NCERT proves more of them than we do. In Class 10, NCERT proves four of twelve against our one. In Class 11 Straight Lines, it proves six of seven against our one of five. In Class 12, it proves ten of thirteen against our six of fourteen. Three of our pages say a result is proved when it is not, and those pages are being fixed. Three of the guides prove every result we checked in them.

How we counted

Three chapters per class: Class 10 Quadratic Equations, Triangles, Statistics; Class 11 Sets, Straight Lines, Limits and Derivatives; Class 12 Matrices, Integrals, Probability. Why-language is a fixed list of words (why, because, the reason, notice, this means, in other words, that is why, the point is, think about, what if). It is counted per 1,000 words, exercises excluded. A mistake box names a wrong step or belief and corrects it. A worked example is one the book itself labels as an example. Derivation means whether a named result is proved in full, sketched, or stated bare. The guides were read from scanned pages; long chapters only to their first forty to sixty pages. Counted October 2026.

Records EV-2026-10-0001 to EV-2026-10-0005, held by Manthika; ask and we send one

What exists today

One language made, three not yet

The demonstrator shows an adult-numeracy topic with its questions fully in Hindi. Which books have a Hindi edition is measured on the status page. No language other than Hindi has started.

See what else is live or soon