Number Detective: Every Number Is a Suspect. Only One Is Guilty.
A hundred suspects line up on the page, 1 to 100 in ten tidy rows. Three witness statements sit underneath: Less than 25. Divisible by 8. Ends in 4.
Your reader picks up a pencil and starts with Ends in 4. Ninety suspects walk free in one stroke. Less than 25 clears seven more, Divisible by 8 clears two, and one number is left standing. It fits every statement. Case closed: it was 24.
That is Number Detective, the thrill of a whodunit played with numbers instead of names. It is Windows software that generates printable math deduction puzzles like this one, at four levels, each case with its own answer page.
Deduction puzzles sell, and the shelf is crowded with them. The culprit isn’t Alice, the butler was never in the library, and a logic grid of ticks and crosses spreads across page after page while plenty of readers close the book at the instructions. Number Detective hands them the same “I cracked it” moment in a few minutes, on one page, to anyone who knows what “even” means.
You choose the chart and the level. Number Detective writes the clues and proves every case against the whole chart before it reaches your page.
Try the free Windows demo and make your first case, or solve one in your browser right now, nothing to install.
A Number Logic Puzzle Anyone Can Solve, on One Printable Page
Your readers love the feeling of cracking a case. What they do not love is a sprawling logic grid with a rules page in front of it.
Number Detective keeps the feeling and drops the homework. The whole rule set fits in one line: cross out every number a clue rules out, and the number left standing is the culprit. A young solver can close a two-clue Very Easy case on day one. An adult reaches the Hard cases, where primes, square numbers and digit sums do the hiding, and still has to think. And the whole case fits on a single page: the chart on top, the numbered clues underneath, nothing to flip back and forth.
I’m Hans, and I build Puzzle Maker Pro. Everyone enjoys catching a culprit, so I built the version you can solve with a pencil and no rules page, the one you can hand to anyone at the table. If you already publish sudoku or other number puzzles, this is the gentle number section to put in front of them.
Printable Math Puzzle Books, Worksheets and Case Files You Can Create
One chart, four levels, two kinds of page, and a catalog’s worth of cases.
A detective case-book that grows with the reader: two-clue Very Easy cases at the front, four-clue Hard cases at the back, every page titled “Case File”. A find-all worksheet pack for the classroom, where the heading reads “Find ALL numbers that are:” and the class circles every number that fits. A times-table investigation with Creative, where a twelve-number chart holds the 7 times table and the clues hunt for one product. A strategy lesson, where the bonus question asks which clue eliminated the most numbers and the answer page prints the winner.
Every puzzle arrives as a pair: a case page and a separate answer page, with each answer circled and printed under the clues. Collect the answer pages at the back of a book, or ship them as a separate teacher set with a worksheet pack.
No Two Culprits, No Filler Clues: Every Case Proven Against the Whole Chart
The fastest way to lose a puzzle reader is a case with two culprits, or a clue that turns out to do nothing. Before a case reaches your page, Number Detective has tried it on every suspect on the chart and thrown it out if anything is off.
Each clue clears at least one suspect and spares at least one. Each clue clears a suspect that every other clue would let through, so every clue on the page earns its place. No clue kind appears twice, so you never get two “Divisible by” clues doing one job. With One culprit on, the default at every level, exactly one number survives, and the answer page is right because the whole chart proved it. Switch One culprit off and two to ten numbers survive, for find-all pages. With the bonus question on, one clue is guaranteed to clear strictly the most numbers, so that question has a single right answer too.
You never write a clue and you never check one. No two puzzles in one run (one press of Create, or one Time Saver row) share a clue set, so a whole series comes out of a single run.
Who This Is For
Puzzle book publishers. You know deduction sells, and you know how long a logic grid takes to build and check. Number Detective puts a detective title in your catalog that a whole family can solve, graded from two-clue warm-ups to four-clue cases. It works like the modules you already own: the same presets and Smart Titles on every edition, the same Time Saver rows with Productivity, and the same Instant Puzzle Books and Puzzle Book Studio.
Teachers and Teachers Pay Teachers sellers. This is number sense dressed as a mystery. Very Easy (odd and even, greater and less than, between, ends in) suits roughly grades 1 to 2. Medium brings in divisibility, the tens digit and digit counts for multiplication and factor work, roughly grades 3 to 4. Hard adds primes, square numbers and digit sums for grade 5 and up. Give three groups the same hundred chart at three levels with one run per level on any edition, or three Time Saver rows in one run with Productivity. Print find-all worksheets for practice, and use the bonus question to start a talk about strategy.
Parents and homeschoolers. A Very Easy case on 1 to 50 is two clues and one triumphant circle, a five-minute win at the kitchen table that quietly practises odd and even, comparing numbers and the ones digit.
Site owners and course creators. With an Interactive edition, a free set of cases becomes a playable path on your site, with your own call to action waiting when the last case is closed.
If you have been skipping deduction puzzles because a logic grid is a day’s work, or printing the same “mystery number” sheet everyone else uses, here is what changes: you choose the chart and the level, and a whole run of cases arrives with its answer pages, ready to print.
Build Your Number Detective Book: Levels, Find-All Pages and Times Tables
Grade a whole case-book from two-clue warm-ups to four-clue brain-teasers
Page one is a two-clue warm-up a young solver can close; the last page needs primes and digit sums. You pick the level, and Number Detective picks how many clues each case gets and which kinds come into play:
| Level | Clues | Clue kinds in play |
|---|---|---|
| Very Easy | 2 | even, odd, greater than, less than, between, ends in |
| Easy | 3 | the same kinds as Very Easy |
| Medium | 3 | adds divisible by, not divisible by, tens digit, number of digits |
| Hard | 4 | adds prime, not prime, square numbers, digit sums, repeated digits |
On a very small or patterned chart, a level from Easy up uses one clue fewer rather than print a clue that does nothing.
Flip one switch for find-all worksheets
Want the classic “circle every number that…” sheet? Turn One culprit off and the heading changes to “Find ALL numbers that are:”, two to ten numbers survive, and the solver circles every one. It works at any level, with its answer page.
Times Table Puzzle Worksheets: Turn Multiplication into a Crime Scene (Creative)
Your lesson this week is the 7 times table, so make the 7 times table the suspects. With Creative, set the formula to n*7 and the count to 12 and the chart holds 7 to 84; raise the count for a multiples-of-7 challenge. n^2 with a count up to 99 gives the square numbers, and 2*n+1 the odd ones. Paste your own list of numbers for a lesson’s exact set, pick a handful at random from a wider range, or shuffle the chart into random order so the hunt itself becomes part of the puzzle. Every chart holds 10 to 400 different whole numbers, from 0 to 9999.
n*7, count 12): greater than 14 and less than 35 leave 21 and 28, and even catches 28.Add the bonus question that teaches strategy
Which clue did the heavy lifting? Tick “Ask which clue eliminated the most” and every case asks the solver exactly that. The answer page prints the clue and how many numbers it removed, and in class it starts the best conversation on the page: the strongest clue is usually the smartest place to start.
Tune the clues to your reader
Writing a Hard challenge book for ten-year-olds? Switch primes off and the hard cases lean on squares, digit sums and repeated digits instead. Eleven clue families each have their own switch, all on by default.
Dress it as a case file
Smart Titles label every page for you, with Number Detective, Case File, Puzzle or your own text, so a hundred book pages carry their titles without a single one typed. Set the numbers font, the canvas and cell colours, the grid lines and the answer circle once, save it as a preset, and your house look comes back with one click on the next book.
From One Case to a Full Printable Case-Book
One case is a page. A puzzle book is a hundred of them, graded from easy to hard.
Every edition builds the book. Set your trim size, margins and layout once, and Instant Puzzle Books lays out a print-ready book PDF in one step, with a title page, a table of contents, and a footer on every puzzle that tells your reader exactly which page its solution is on. At one case page and one answer page per puzzle, 50 cases fill a 100-page puzzle-and-solution interior.
Puzzle Book Studio, also on every edition, is the page-by-page editor for one puzzle collection: book themes and page art, your own text and how-to-play pages, per-puzzle titles, and saved book projects.
With Number Detective Productivity, Time Saver builds the whole run in one pass: give each row its own preset, level and quantity, and generate them together. Set 40 Very Easy, 40 Medium and 20 Hard in three rows, add a fourth with One culprit off for a find-all section, run once, and the whole graded run arrives with its answer pages, ready for Instant Puzzle Books or Puzzle Book Studio to bind into the book. Productivity also brings Puzzle Book Studio Productivity, which combines several collections in one book, so a Number Detective section can sit beside your other puzzle types.
Case Pages Ready for KDP, Worksheets and Vector Layouts
Drop the same case into a KDP interior, a classroom PDF or an SVG layout, and it looks identical in all three. Number Detective exports PNG, JPG, SVG and PDF for every case page and every answer page, and the PDF and SVG files are vector, so they stay sharp at any trim size. Printing a black-and-white interior? Set the answer circle to black and the key reads cleanly on any paper.
Play It on the Web (Interactive Editions)
A Number Detective case is one of the easiest puzzles to hand a website visitor, because the rules fit in a single sentence and the board does the rest.
Publish a set to your site through the free Puzzle Maker Pro Online WordPress plugin and readers solve it by elimination. They pick a clue and click the suspects it rules out, and each one fades to grey. Strike a number the chosen clue does not rule out and it flashes red and stays put, so the board only accepts deductions, never guesses. A “Remove all for this clue” button clears the rest in one go. When only the culprit is left standing (or, on a find-all page, every answer), each survivor gets its red circle and the case is solved.
Publish the set as a puzzle list and visitors pick a case from a dropdown. Publish it as a leveled game and it becomes a path of cases that unlock in order, with each visitor’s progress saved in their own browser. Rename “Level” to “Lesson” and the same path becomes self-paced number practice you can link from a class page. When a solver closes the last case, the completion screen shows your own message and your own button, so a free set of ten cases ends on “Get the full case-book” at exactly the moment they want more.
Play Number Detective in your browser
Which Edition Should You Choose?
Start with the cases. Add your own suspects with Creative, volume with Productivity, and the web with Interactive.
Number Detective (Standard): you want the cases and the printed pages. Every level, one-culprit cases and find-all worksheets, the bonus question, all four export formats, and ready-to-print books with Instant Puzzle Books and Puzzle Book Studio, on any run of numbers in order, such as 1 to 100.
Creative: you want to choose the suspects. Formula charts for the times tables, your own number lists, numbers picked from a wider range, and shuffled charts.
Productivity: you are making books and packs in volume. Time Saver batch runs, books that combine several collections, JSON export, and the right to sell or supply the generated puzzles to other publishers and sellers.
Creative + Interactive / Productivity + Interactive: you want your cases playable on your own website, as a list or a leveled game.
| Standard | Creative | Productivity | |
|---|---|---|---|
| Create Number Detective cases at all four levels, from Very Easy to Hard | ✓ | ✓ | ✓ |
| One-culprit cases and find-all worksheets | ✓ | ✓ | ✓ |
| Bonus question and all eleven clue families | ✓ | ✓ | ✓ |
| Export as PNG, JPG, SVG and PDF, case page and answer page | ✓ | ✓ | ✓ |
| Style colours, lines and fonts | ✓ | ✓ | ✓ |
| Instant Puzzle Books: a ready-to-print book from your current settings, with title page, table of contents and solution cross-references | ✓ | ✓ | ✓ |
| Puzzle Book Studio: full book design, one puzzle collection | ✓ | ✓ | ✓ |
| Custom charts: pick from a range, your own number list, formula charts such as n*7, random order | ✓ | ✓ | |
| Time Saver: batch-produce complete unique sets | ✓ | ||
| Puzzle Book Studio Productivity: mixed books from multiple collections, plus external puzzles | ✓ | ||
| JSON export: puzzle data files for your own apps and workflows (Time Saver does not include this) | ✓ | ||
| Licence to sell finished books, worksheets, and packs to your own readers and customers | ✓ | ✓ | ✓ |
| Licence to sell or supply generated puzzles to other publishers and sellers | ✓ | ||
| + Interactive (on Creative or Productivity): publish playable web games on your own site, as a list or a leveled game | ✓ | ✓ |
Interactive is an add-on: it stacks on Creative or Productivity and carries everything that edition has.
You can upgrade to a higher edition later, so pick the one that fits what you are making today. Already own other Puzzle Maker Pro modules? Puzzle Maker Pro Editions Explained shows how editions work across products.
Ready? Choose your edition in the edition switcher at the top of this page.
Try It Before You Buy
Solve a case and make one yourself before you spend anything. The free Windows demo covers every current puzzle module and generates real Number Detective puzzles, one watermarked image at a time, so you can see the levels, the one-culprit cases and the find-all pages coming out of the software. Want the solver’s view first? Read how Number Detective puzzles work, or see how to create Number Detective puzzles step by step.
Licensing and Commercial Use
Commercial rights. Number Detective and Number Detective Creative both let you sell the finished books, worksheets, and packs you make to your own readers and customers, on KDP, Etsy, Teachers Pay Teachers, or your own store. One-time commercial-use licence. Watermark-free. Number Detective Productivity includes that, plus you may sell or supply the generated puzzles to other publishers and sellers.
The + Interactive editions carry the same rights as the edition they are built on.
Product Details
| Product | Number Detective |
| Editions | Number Detective, Number Detective Creative, Number Detective Creative + Interactive, Number Detective Productivity, Number Detective Productivity + Interactive |
| Platform | Windows desktop |
| Internet required | Not for generating, styling or printing; yes for publishing web play to your own site |
| Levels | Very Easy (2 clues), Easy (3), Medium (3), Hard (4) |
| Answer shapes | One culprit (exactly one number survives, the default) or find-all (2 to 10 numbers survive) |
| Charts | 10 to 400 different whole numbers from 0 to 9999, in 2 to 20 columns; custom number sources and random order with Creative and up |
| Outputs | PNG, JPG, SVG, PDF (PDF and SVG are vector), case page and answer page |
| Solution pages | Yes, a separate answer page for every puzzle, each answer circled |
| Puzzle books | Instant Puzzle Books (all editions); Puzzle Book Studio for one collection (all editions); books combining several collections (Productivity); title page, table of contents and solution cross-references on every edition |
| Time Saver | Productivity and Productivity + Interactive |
| JSON export | Productivity and Productivity + Interactive |
| Play on the web | Creative + Interactive and Productivity + Interactive, as a puzzle list or a leveled game |
| Commercial licence | Sell finished books, worksheets, and packs to your own readers and customers; Productivity adds selling or supplying the generated puzzles to other publishers and sellers |
| Free demo | Yes |
| Delivery | Immediate, in your member area |
Questions Before You Buy
Is there a free demo?
Yes. One download covers every current puzzle module and generates real puzzles, watermarked and one at a time, so you can make a Number Detective case before you decide. You can also play a case in your browser right now.
Can I upgrade later?
Yes. You can upgrade to any higher edition at any time after you buy: Creative for your own charts, Productivity for volume, and Creative + Interactive or Productivity + Interactive when you want your cases playable on your own website. Start with the edition that fits what you are making today; you are never locked into it.
Does every case have exactly one answer?
With One culprit on, the default at every level, yes. Turn it off for find-all pages, where two to ten numbers survive and the heading says so.
Do I have to write the clues?
No. Number Detective writes every clue and builds the answer page for you.
Which level suits which solver?
Very Easy (two clues on even, odd, greater or less than, between and ends in) fits roughly grades 1 to 2. Easy adds a third clue. Medium brings in divisibility and the tens digit, roughly grades 3 to 4. Hard adds primes, square numbers, digit sums and repeated digits for grade 5 and up, and gives adults a proper think.
Can I use my own numbers, like a times table?
Yes, with Creative and up. Use a formula such as n*7 with a count of 12 for the 7 times table, paste your own list of numbers, pick numbers at random from a wider range, or shuffle the chart into random order.
Can two cases in one run be the same?
No two puzzles in one run, or in one Time Saver row, share a clue set, so you can make a whole series in a single run and split it into volumes afterwards.
Will it work for a black-and-white KDP interior?
Yes. Set the answer circle to black, set your trim size and margins in the book settings, and export the print PDF, which stays sharp at any size.
Can my readers play the cases online?
Yes, with Creative + Interactive or Productivity + Interactive. You publish the set to your site with the free Puzzle Maker Pro Online WordPress plugin, and readers cross out suspects clue by clue in the browser, from a puzzle list or along a leveled game.
Can I sell what I make?
Yes. Every edition lets you sell the finished books, worksheets, and packs you make to your own readers and customers. Productivity adds the right to sell or supply the generated puzzles to other publishers and sellers.
Give Your Readers a Case They Can Actually Close
A reader on the sofa, pencil in hand, ten cases into your book, flipping to the answer pages to find they were right all along, and reaching for the next case. That is the book you can make this week.
Every number book on the shelf asks readers to calculate. Yours asks them to catch a culprit, and that is the one they pick up.
Solve one free in the demo, or choose your edition at the top of this page and start your first case-book today.
