inqizit games
Practise thinking, one level at a time.
Games for calculation, memory, pattern and logic. Every level is generated, none is the last, and every answer comes with the truth about it.
- 149 games
- 13 skills
- 105 without a last level
- 0 sign-ups
Calculation 12
Exact answers, worked in the head, against a clock that tightens as you improve.
Mental arithmetic
Add, subtract, multiply and divide in your head, from 3 + 4 upward, with a clock that tightens and numbers that never stop growing.Running total
Numbers flash one at a time — keep the running total in your head and give it at the end. More numbers, bigger, faster, then minus signs.Flash sum
Anzan-style: a burst of numbers flashes past, fast; give their sum. More numbers, more digits each, less time each — the width never stops.Number pyramid
Each brick is the sum of the two beneath it. Find the missing one — at the top, in the middle or at the base — as pyramids grow taller and numbers larger.Letter sums
SEND + MORE = MONEY: each letter is a different digit. Work out what one letter must be — longer words, three addends, subtraction, products.Make the target
Four numbers and a target, 24-game style: which expression uses each number once and hits it? More numbers, bigger ones, all four operations.Magic square
Every row, column and diagonal adds to the same sum. Fill the marked gap — 3×3 up to 7×7, more blanks, bigger numbers, without end.Calendar
If 3 March is a Monday, what day is 27 April? 100 days from Tuesday? Days between two dates, and leap years — with spans that grow from days to centuries.Clock
The angle between the hands at 3:20, and the time 3 h 50 min after 10:45 pm — across noon and midnight, 12- or 24-hour, finer minutes, longer spans.Squares and tricks
65² is 6 × 7 then 25; 97 × 96 is 93 hundred and 12; 47 × 53 is 50² − 3². Mental squaring and near-base products, with numbers that keep growing.Numbers round
Six numbers and a target: reach it with + − × ÷, each number at most once. Any route counts; the targets grow and need more numbers.Find the mistake
A worked calculation with exactly one wrong line — a dropped carry, a lost minus sign, a percentage of the wrong base. Which line?
Number sense 16
Size without the arithmetic: which is bigger, roughly how much, and the money and time of an ordinary day.
Everyday maths
Percentages, discounts, change, splitting a bill, clock times, speed, price per gram, exchange rates and interest — the arithmetic of an ordinary day.Unit conversion
Inches to feet, miles to kilometres, °C to °F, GiB to GB — convert fast, and learn to catch yourself multiplying where you should divide.Quick estimate
Which is bigger, 38 × 21 or 29 × 27? Judge size fast, without working it out — the two sides creep closer every level and never meet.Fermi estimates
Heartbeats in a day, litres in a cube, seconds for sunlight to reach us: estimate to the nearest power of ten by breaking it into factors.Scientific notation
Multiply and divide numbers written as a × 10ⁿ, and convert to and from them — with exponents that keep widening, positive and negative.Divides or not
Does 7 divide 4,571? Which of 2, 3, 4, 9, 11 divide 81,312? Answer by the rules, not by long division — up to 7, 11 and 13, with no limit on digits.Number line
Where does 3/7 sit among the ticks 0, 0.25, 0.5, 0.75, 1? Is 5/9 or 4/7 nearer to ½? Place fractions and decimals, with denominators that keep growing.Place value
What is the 7 in 3,472,105 worth? Round it to the nearest thousand. Write 34,72,105 the international way; 45 lakh in millions. Digits without end.Fractions
3/8 as a decimal, 7/20 as a percent, 0.375 as a fraction, 18/24 in lowest terms, 5/8 against 3/5 — exact conversions with denominators that keep growing.Primes and factors
Is 221 prime? The smallest prime factor of 391? The gcd and lcm of 84 and 126? Numbers built to look prime, and magnitudes that never stop growing.Ballpark
About how big is 4,872 × 316? Round each number to one figure and multiply — the options start powers of ten apart and close in.Digits and logs
How many digits has 2¹⁰⁰? What does 7⁴⁰ start with? Work it out from log 2, log 3 and log 7 — no calculator, and the answer is exact.Last digits and remainders
The last digit of 17²⁰²⁶, 3¹⁰⁰ mod 7, a product mod 9: powers fall into short cycles, and the cycle gives the answer without the number.Energy you can feel
A kettle in kWh, a phone battery in Wh, a snack in kJ and in kettle boils, the cost of lifting a weight: energy, worked out from a few exact definitions.Shrink the universe
If the Sun were a 1 m ball, Earth would be a 9 mm bead 107 m away. Scale the solar system, the Moon and the nearest star, and feel the sizes.Read the chart honestly
Bars that start at 40, "up 5%" that means 5 points, a bigger share of a smaller town: say what a chart really supports, from its numbers.
Memory 12
Holding things in mind — words, digits, places — and getting them back out in the order asked.
Word recall
Words flash past one at a time; then pick out the ones you saw. Lists grow longer, words come faster, and the lures get closer.Digit span
Digits flash one at a time; type them back in order, in reverse, or sorted. One more each level, with no ceiling.Grid memory
Cells light up on a board, then go dark; tap the ones that were lit. More cells, bigger boards, shorter looks.Block sequence
Cells light up one after another; tap them back in the same order — or in reverse. One more block each level, with no ceiling.Numbers vanish
Numbers appear on a grid. Tap 1 and the rest go blank — then tap where 2, 3, 4… were, in order. One more number each level.N-back
Letters arrive one at a time; press when one matches the letter n steps back. 1-back, then 2-back, 3-back — and on, as far as you can hold.Running span
Symbols stream past and stop without warning; type the last few in order. More to keep, longer streams, faster, with no ceiling.Pairs to remember
Study word pairs one at a time; then given one word, pick its partner. More pairs, shorter looks and closer lures as you climb.Story details
Read a short story of who went where, with what and when; it vanishes, and you answer one detail. Longer stories, harder questions, closer lures.Same or changed?
Symbols flash at places on a board, a blank, then they return: same, or has one changed? More symbols, shorter looks, subtler changes.Complex span
Judge a sum true or false, then see a letter; again and again — then recall the letters in order. One more letter each level.Concentration
Pairs of cards lie face down. Flip two at a time, remember what you saw, and clear the board within what a perfect memory would need.
Pattern 7
Finding the rule from the examples and carrying it one step further.
Number sequences
Find the rule behind a run of numbers and carry it one step on — adding, doubling, interleaving, growing gaps — with rules and numbers that keep coming.Letter series
A, C, F, J, ? — find the rule in a run of letters, or letters with numbers, and give the next or the missing term. The rules keep coming.Odd one out
All but one share a property — even, a multiple of 7, square, prime, birds — and one does not. Find it; the properties get subtler as you climb.Analogies
2 : 8 :: 3 : 27 :: 5 : ? and AB : BC :: KL : ? — find the relation in the example and carry it over. The relations grow subtler as you climb.Function machine
Numbers go in, numbers come out. From a few pairs, find the rule — ×3 + 2, square it, reverse the digits — and say what comes out next.Pattern matrices
Nine small boards in a 3×3 grid, the last one missing. Find the rule along the rows — counts, symbols, a walking mark, overlays — and complete it.Hidden rule
Shapes sorted into two piles by a rule you are not told — filled, triangles, three or more. Where does the new one go? Rules grow to “and” and “or”.
Spatial 9
Where things are, which way you face, and where something must go — reasoning about a scene.
Spatial scenes
A board of things: what is left of the cone, where do two moves right and one up land you, which way do you face — and where must the new thing go?Turn it in your head
A pixel shape: which picture is the same shape turned, not flipped? Mirror images and near shapes stand in the way, and the shapes keep growing.In the mirror
A shape beside a mirror line: which picture is its reflection? The wrong ones are copied, turned, reflected the other way or one cell off.Fold and punch
A square sheet is folded in half, then again, and punched through. Which picture shows the holes when it is opened out? More folds, punches and squares.Lines of symmetry
Does the pattern fold onto itself along an upright line, a flat one, both or neither? Later: how many ways does it turn onto itself?Direction sense
Walk 3 m north, turn right, walk 2 m… Where are you now from the start, and how far in a straight line? Longer walks, told by turns.Fold the cube
Six labelled squares fold into a cube. Which face ends up opposite this one? Which two never touch? Is it a proper die? All eleven nets.Count the squares
How many squares of every size are in a grid — or how many rectangles? Count by the formula, not by staring, as the grids grow without end.Count the routes
Moving only right or down, how many routes run from A to B around the blocked squares — or through the ●? Count them exactly, square by square.
Attention and speed 14
Seeing the one thing that matters, fast, while everything else tries to pull your eye.
Schulte table
The numbers 1 to N scattered on a grid: tap them in order, fast. The board grows each level; then letters, then numbers and letters taken in turn.Go / no-go
Press for the go items, fast — and hold back on the others, which come rarely and look more and more like them.Arrow flanker
A row of arrows like ← ← → ← ←: which way does the middle one point? More flankers, more of them pointing the wrong way, and less time.Count, don’t read
A row like 3 3 3 3: how many are there, not what do they say? The printed digit pulls against the count. More conflict, less time, as you climb.Odd or big?
A number with a cue: ODD? or BIG? (more than 5). Answer yes or no for the rule shown; the rule keeps changing. More clashes, less time.Where, not what
A word like LEFT sits somewhere around a centre: answer where it is, not what it says. More clashes, the diagonals, less time as you climb.Find the odd one
A board of identical symbols hides one that differs: find it. Bigger boards, and odd ones that differ less — hollow, upside down, mirrored.Cancellation
A board of symbols: find every one of the target — the count is told — while lookalikes try to pass for it. Bigger boards, closer lookalikes.Spot the change
A board of symbols, a blank, the board again with one cell changed: tap it. More symbols, shorter looks and subtler changes as you climb.Symbol code
A legend pairs symbols with digits; translate a symbol, then strings of them, into digits fast. Bigger codes, longer strings, a fresh legend each time.Clerical match
Two numbers, codes or names, one above the other: exactly the same, or not? Longer strings and subtler differences — swaps, lookalikes — as you climb.How many?
Dots flash on a board for a moment, then a mask: how many were there? More dots and shorter flashes, with no top count.Reaction
Dots tick by; press the instant ● appears. The window shrinks every level, and some runs never bring the ● at all.Inner clock
Nothing changes on screen. Press when you think the stated number of seconds has passed — the window narrows and the times grow.
Words 9
Letters and words: rearranging, decoding, grouping and finding what fits.
Anagrams
The letters of a word, scrambled: T L I P U. Put them back — TULIP. Longer words as you climb, and the hint of what kind of thing it is fades away.Coding and decoding
If CAT is coded as DBU, what is EPH? One example shows a code — a shift, a reversal, a mirror, letters as numbers. Find it, then code or decode a word.Groups of four
A board of 12 to 20 words, and exactly four are the same kind of thing. Find them among near misses that come in threes. Connections, one group at a time.Hidden word
A string of letters hides one word — a bird, a tool, a country. Which of the options is in there? The strings grow longer without end.Letters
A handful of letters and four words: exactly one can be spelled from them. Spot it before the clock — the words grow longer.Word sweep
A page of words: tap every fruit, every tool, every colour — before the clock. More words each level, and then lures of a nearby kind.Word ladder
COLD to WARM, one letter at a time, every rung a word. Which word is the next rung on a shortest ladder? Ladders grow longer.Word deduction
Find a hidden five-letter word from letter clues. Each turn, pick the offered word that fits every clue so far — no guessing, only deduction.Word roots
Chronophobia, ichthyologist, frugivore: work out what a word must mean from its Greek and Latin roots — including words nobody has ever used.
Logic 35
Slow thinking: what must be true, given only what you were told.
Who is tallest?
From shuffled comparisons — Ana is taller than Ben, Cleo is shorter than Ana — build the line in your head and say who stands where.Off by one
Fence posts, cuts, floors, inclusive pages, a striking clock, lists numbered from zero — count the ends right, every time, at speed.Knights and knaves
Everyone on the island always tells the truth or always lies. From what they say, work out who is which — more islanders, harder sentences.Syllogisms
All wugs are daxes; some daxes are feps. Does it follow that some wugs are feps? Judge conclusions about made-up kinds, from two premises to long chains.If–then
If P then Q. Q. So P? Tell the valid if–then arguments from the fallacies that look just like them, from one rule to long chains.Which cards to turn
A rule, some cards, and only one side of each showing. Pick exactly the cards that could break the rule — the test most people fail.Overlapping sets
Seventy like tea, fifty like coffee, thirty like both — how many like neither? Count overlapping groups without counting anyone twice.Logic grid
Three to five people, each with a different pet, drink or home town. From a handful of clues, work out who has what.Seating arrangement
Who sits where? From clues like “Asha sits at one end” and “Bilal is immediately left of Chen”, place everyone in a row or round a table.Blood relations
Ravi is Meena’s mother’s brother — what is Ravi to Meena? Follow chains of family words, from two steps to as many as you can hold.Truth tables
P AND NOT (Q OR R), with P = 1, Q = 0, R = 1 — is it 1 or 0? Evaluate logic expressions and gate circuits, find the inputs that light them, count the 1s.Does it follow?
P: it rains. If P, then Q. Not Q. So: not P? Decide whether a conclusion follows from premises written in letters, checked by the full truth table.Latin squares
A small grid where every row and column holds 1 to n exactly once. Find the number in the marked cell, from 3×3 up to 7×7, or fill the whole square.Nim
Heaps of counters; take any number from one heap; whoever takes the last wins. Pick the winning move — or see that there is none — by the XOR rule.Tower of Hanoi
How many moves does a Tower of Hanoi of n disks take? Derive 2ⁿ − 1, then count from a position part-way through, and with neighbouring pegs only.Find the fake coin
Twelve coins, one fake, a balance: how many weighings, at worst? Derive the base-3 bounds for a heavier coin and for one that may be either.Water jugs
A 3-litre jug, a 5-litre jug and a tap: can you measure exactly 4 litres, and in how few steps? Decide by the gcd rule; count by the shortest route.Trap questions
Bat-and-ball questions with fresh numbers every time: the first answer that comes to mind is wrong. Catch it, then work it out.Codebreaker
Deduce a hidden code from ● and ○ clues. Each turn, pick the guess that fits every clue so far. Longer codes and more letters, without end.Higher or lower
Find a hidden number from what each guess says: higher or lower. Halve what is left each time and you never need more than log₂ guesses.Lights Out
Each press flips a cell and its four neighbours. Turn every light off in the fewest presses — par is the exact optimum, solved over GF(2).Sliding tiles
Slide the numbered tiles into order, one into the gap at a time, within a par set by the exact fewest moves — 2×3 up to 3×4 boards.River crossing
Wolf, goat and cabbage; missionaries and cannibals; soldiers and boys. Get everyone across without breaking a rule, in the fewest crossings.Tower of Hanoi
Move the stack to peg C one disc at a time, never a large on a small, in the fewest moves: 2^n − 1 from the start, fewer from a scattered one.Mini sudoku
Fill the grid so every row, column and box holds each digit once — 4×4, then 6×6, then 9×9, with fewer givens as you climb.Inequality grid
A Latin square with < and > signs between cells: place each number once per row and column so every sign holds. 4×4 up to 7×7.Binary grid
Fill the grid with 0s and 1s: no three alike in a line, equal counts in every row and column, no two lines the same. 4×4 up to 10×10.Skyscrapers
Place buildings of heights 1 to n, once per row and column, so the edge numbers count how many you see from each side. 4×4 up to 6×6.Cross sums
Fill white cells with 1 to 9 so every run adds to its clue, with no digit twice in a run — small boards first, growing.Queens
Place one queen in every row, column and lettered region, with no two touching — 5×5 up to 9×9, each with exactly one answer.Picture by numbers
Fill the squares the row and column numbers describe — each number a run of filled squares, in order. 5×5 up to 10×10, one picture each.Mine logic
Numbers count the mines around them. Mark every hidden square as a mine or safe — no guessing, exactly one answer. Fields grow from 5×5.Cage sums
Fill a Latin square so the numbers in each cage make its target by its sign — adding first, then all four operations. 4×4 up to 6×6.Name the fallacy
Ad hominem, straw man, false dilemma, post hoc, slippery slope: read a short argument and name the one move it makes. Fresh wording each time.Bridges
Join numbered islands with straight bridges, one or two per pair, never crossing, all in one group. Small boards first; every puzzle has one solution.
Quantitative reasoning 8
The quant of exams and offices: work and time, mixtures, ratios, ages, series — derived, not memorised.
Counting
Podiums and committees, the letters of BANANA, a round table, "at least one", sweets shared out: count exactly, and know which formula and why.Quadratics by inspection
Roots of x² − 5x + 6 at a glance: two numbers with the right sum and product. Then leading coefficients, the discriminant, and sum and product of roots.Which formula can be right?
The pendulum's period: √(L/g) or √(g/L)? Units decide. Pick the one formula whose kilograms, metres and seconds come out right.Work and time
A does a job in 12 days, B in 18 — how long together? Pipes, leaks, workers who leave midway: add the rates, never the times.Mixtures
Dilute an acid, blend two prices, draw off milk and refill with water — find what is conserved, and the mixture works itself out.Ratios and ages
Share ₹1,200 in the ratio 3 : 5, chain A : B with B : C, find an age from what it will be — one part first, then count the parts.Trains and streams
A 150 m train at 54 km/h clears a 300 m platform in how long? Relative speed, boats against the stream, round-trip averages.Series and sums
The 40th term of 3, 7, 11, …; 1 + 2 + … + 100; the first 50 odd numbers; a geometric sum — each derived from pairing ends or shifting terms.
Money 7
Compounding, loans, present value, margins and break-even — the arithmetic money actually runs on.
Bonds and yields
Yields up, prices down — and by how much. Price a bond from its coupon and yield, read premium or discount, and see which bond falls more.The cost of exchange
A bureau sells high and buys low, then adds a fee. Work out what changing money really costs: the side of the board, the round trip, the cross rate.How much to bet
A bet with an edge, made again and again: how much of your bankroll to stake. The Kelly fraction, why over-betting loses, and what half-Kelly keeps.Interest and doubling
Simple against compound interest, the rule of 72 beside the exact doubling time, and what 12% compounded monthly really pays in a year.What a loan costs
The EMI on a loan, the interest paid over its life, a flat rate against a reducing one, and how much a monthly budget can really borrow.Present value
What ₹1,00,000 in five years is worth today, real against nominal returns, a stream of payments and a project's NPV — money moved through time.Margins and break-even
Margin against markup, a discount on a discount, profit and loss on cost, and how many units before a business breaks even.
Probability 6
Chance, base rates and expected value: what to believe, and what a bet is worth.
How sure are you?
A quick claim — 17 × 23 = 391, 1 mile is more than 1.5 km — and seven taps for how sure you are it is true. Scored so honesty pays.Ninety per cent sure
How many minutes in a week? Give a low and a high you are 90% sure hold it. A range that holds the truth scores; a narrow one scores more.The reversal
A treatment can win in every group and still lose overall. Read results by group and in total, and work out which comparison to trust.Dice, coins and cards
The chance of a 7 with two dice, of at least one six in four rolls, of two aces in a row — counted out exactly, and given as a fraction.Base rates
A test catches 90% of cases and wrongly flags 9% of the rest; 1% have it. You test positive — what is the chance it is real? Count it out.Expected value
What a bet is worth on average: a paid spin, a fair price, a raffle ticket, an insurance policy, a wheel's house edge, and which of two bets is better.
Geometry and trigonometry 5
Angles, triangles, circles and the unit circle, worked in the head.
Unit circle
sin 150°, cos 5π/4, tan 300°: exact values from the two special triangles and the sign of the quadrant, in degrees and radians.Triangles and polygons
Missing sides by Pythagoras, the 30-60-90 and 45-45-90 triangles, polygon angles and areas — geometry worked in the head, at growing sizes.Circles
Circumference, area, arc length and sector area, with π kept exact or worked out — the circle formulas, fast and without mixing them up.Coordinates in the head
Which quadrant, how far apart, the midpoint, the slope, the line through two points, the distance to a line: coordinate geometry, exact, without paper.Small angles
sin 4° is about 0.0698 because 4° is 0.0698 radians. Use sin θ ≈ tan θ ≈ θ, know how far off it is at 20°, and size things from the angle they fill.
Computing 9
Bits, bases, powers of two, complexity and the numbers every programmer should feel.
Binary and hex
Binary to decimal, decimal to hex, hex to binary — convert between the bases a computer is written in, at a width that keeps growing.Bitwise
AND, OR, XOR, NOT, shifts, x AND (x − 1) and two's complement, worked bit by bit at a width that keeps growing.Powers of two
2ⁿ and back, GiB to MiB, and how many bits a number of values needs — the powers of two a programmer should have at hand.Big O by inspection
A few lines of loops or recursion: say how the work grows — O(n), O(n log n), O(n²), O(2ⁿ) — by reading the shape, not running it.Latency numbers
How many memory reads fit in a disk seek? Feel the gaps between cache, memory, disk and network, to the nearest power of ten.Data structures by hand
Push, pop, insert, probe: trace a stack, a queue, a search tree, a heap and a hash table by hand, and say what comes out or what the array holds.What does this query return?
A tiny table, a short SQL query: say what comes back. COUNT(*) or COUNT(x), NULL in a WHERE, LEFT JOIN counts, and NOT IN with a NULL.Race conditions
Two threads each run x = x + 1 twice. Can x end at 2? Work out every value a race can leave — every interleaving is checked by running it.Subnets on sight
Hosts in a /26, the network address of 192.168.10.77/26, the mask of a /20, same subnet or not: IPv4 subnetting, exact, in your head.
How the levels work
Your level is judged on your most recent answers — by default the last ten, every ten. Score 90% or more and you move up; below 80% and you move down; in between you stay. Those defaults hold most people near four answers in five right — hard enough to learn from, not so hard it becomes guessing.
Each level turns one dial one notch: bigger numbers, more items, a harder kind of question, or less time. Every rule is a setting, and your progress is kept in this browser and nowhere else.
What this does not claim
Practice makes you better at what you practise. The research on brain training is clear that it does not, on its own, make you more intelligent or improve unrelated skills, and no page here says otherwise. Each game states what it can honestly be said to train.
Every game has a Learn section: the method, the tricks, how to meet each new level, and the traps.