Tap the card that does not belong, then crack the Secret Gate: three cards get in, three are turned away, and your child picks the next card that passes. Six levels, a daily set and printable worksheets.
Sorting things by a rule that nobody states is the first step of set thinking, and it is a favourite question type in children's maths and logic contests. This game builds that skill: a child looks at a handful of picture cards, works out what most of them share, and finds the one that breaks the pattern. The cards are drawn from four things: the shape (circle, triangle, square or hexagon), the fill (solid, striped or hollow), the size (small or big) and how many shapes are on the card (one to four). Some puzzles use emoji pictures instead, such as animals, fruit or things that go. It is made for a child of about 6 or 7 who can match and count, and level 1 can be played on the first day. The top levels are hard on purpose: they ask the child to hold two tests in mind at once.
Level 1 shows four cards. Three are exact copies and one differs in shape, fill or size. Level 2 shows four cards that agree on one thing, the shape, fill, size or number of shapes, while the other things change from card to card; some puzzles at this level use emoji from a group such as animals, fruit, sports balls or clothes. Level 3 shows five cards and asks about an odd or even number of shapes, or about corners: a circle and a triangle have fewer than 4 corners, a square and a hexagon have 4 or more. Level 4 shows five cards where each of the others is one thing or another, such as striped or small, and the odd card is neither. Level 5 is the Secret Gate. A tray of three cards that got in and a tray of three that were turned away are shown, and the child picks which of four new cards the gate lets in. Level 6 is the same, but the gate's rule has two parts joined by and or or.
A puzzle is not just drawn at random and trusted. After the game builds a set of cards, it lists 384 possible rules: tests such as is striped, is not a circle or has at least 3 shapes on the features (shape, fill, size, number of shapes, odd or even, corners), plus every pair of two tests joined by and or or. Counting rules such as at least 3 shapes and at most 2 shapes are in the list because a child counts that way as naturally as with an exact number. In an odd one out puzzle it requires that every rule that turns away exactly one card turns away the same card, so there is no second answer hiding behind a different rule. In a Secret Gate puzzle it keeps every rule that fits the six examples and requires that the right card passes under all of them and each wrong card fails under all of them. The tests repeat these checks on 500 seeds for every level with a separate search. The emoji puzzles use hand-picked groups, such as wild animals, pets, farm animals, fruit, things that go, sports balls, instruments, clothes, weather, trees and flowers, so a puzzle never mixes pets with wild animals in the same set of three. A puzzle shows three cards from one group and one from a group of a different kind, and never fruit with trees or flowers, because fruit grows on plants. A puzzle is also dropped when three of its cards share a colour that the odd card does not. The game cannot prove that no other link exists between two pictures, and picture art differs a little between phones.
Print a worksheet by choosing the level, 4, 6 or 8 puzzles, and Letter or A4 paper. Each sheet is made from new puzzles, and the answer key with a short reason for each answer is on the last page. A worksheet is drawn in black and white, so the card shapes never rely on colour: the fill is a pattern, and every card in a puzzle shares one colour on screen. The daily set, Today's 5, is made from the date on your device, so a child who plays on two devices on the same day sees the same five puzzles. The game has no timer by default, no ads inside the play area and no account, and a speaker button reads each question aloud with your device's voice. It does not mark a child's work for a school, it does not replace a maths curriculum and it does not keep scores anywhere except in this browser.
It is made for a child of about 6 or 7. Level 1 shows four cards where three are copies, which a child who can match pictures can do on day one. Levels 5 and 6 are the Secret Gate, which asks for a rule with up to two parts, so a child may need several tries before the idea clicks.
Not under the rules the game checks. Each puzzle is tested against 384 rules, single tests and pairs of tests joined by and or or, and only one card can be turned away. Emoji puzzles use hand-picked groups and are dropped when a shared colour would point at a different card, but a child may still notice another link that the game does not count.
The gate lets in some cards and turns others away. The game shows three cards that got in and three that did not, and four new cards. The child picks the one the gate lets in. At level 5 the rule is one test, at level 6 it is two tests joined by and or or.
Choose a level, 4, 6 or 8 puzzles and Letter or A4. The sheet is made in your browser from new puzzles each time, in black and white, and the last page is an answer key with the reason for each answer. Nothing is uploaded.
A worksheet is often printed in black and white, and some children cannot tell certain colours apart. So the difference between cards is always a shape, a pattern, a size, a count or a picture, and all the cards in one puzzle share one colour on screen.
Only in this browser, on this device: the level, stars and daily progress are saved in local storage and nothing is sent anywhere. The page counts visits with Google Analytics, never answers or names. Clearing site data for this page removes the saved progress.