Page 1 · Introduction
Which one is different?
In an ‘odd one out’ puzzle, most things share something in common — and one doesn’t fit. The trick is to work out the rule the others follow, then find the one that breaks it.
The big ideaFind what most of them have in common — the group rule. The odd one out is the one that doesn’t follow that rule.
💡We look at groups of words, numbers and shapes. Ask: ‘what do most of these share?’ first.
On the real testWhere this appearsOdd-one-out puzzles are common in the Thinking Skills section of the OC test (sat in Year 4). Find the group’s rule first.
Page 2 · Groups of words
What do they share?
Work out what most of the words have in common, then spot the one that’s different.
Which is the odd one out? apple, banana, carrot, orange
Apple, banana and orange are fruits. Carrot is a vegetable — the odd one out.
Carrot
Page 3 · Groups of numbers
Number rules
Look for a number rule — like all even, all big, or all in a times table.
Which is the odd one out? 2, 4, 7, 8
2, 4 and 8 are even. 7 is odd — the odd one out.
7
Page 4 · Groups of things
Sorting by type
Things can be grouped by what they are or what they do.
Which is the odd one out? dog, cat, fish, rabbit
Dog, cat and rabbit have fur and legs. A fish is different — it lives in water and has no legs.
Fish
Level 1 · Easy
Warm up
Find the different one. Tap to check.
1. Which is the odd one out? red, blue, green, apple
A red
B blue
C apple
D green
Red, blue and green are colours. Apple is a fruit.
2. Which is the odd one out? cat, dog, horse, table
Cat, dog and horse are animals. Table is furniture.
3. Which is the odd one out? 2, 4, 6, 9
2, 4 and 6 are even. 9 is odd.
Level 2 · Medium
Building up
Work out the group rule.
1. Which is the odd one out? car, bus, boat, train
Car, bus and train travel on land. A boat travels on water.
2. Which is the odd one out? rose, tulip, daisy, oak
A rose
B oak
C tulip
D daisy
Rose, tulip and daisy are flowers. An oak is a tree.
3. Which is the odd one out? 10, 20, 25, 30
10, 20 and 30 are in the 10 times table. 25 is not.
Level 3 · Hard
Getting tougher
Trickier groups.
1. Which is the odd one out? circle, square, triangle, red
A circle
B red
C square
D triangle
Circle, square and triangle are shapes. Red is a colour.
2. Which is the odd one out? 3, 6, 9, 10
3, 6 and 9 are in the 3 times table. 10 is not.
3. Which is the odd one out? shoe, sock, boot, hat
Shoe, sock and boot go on your feet. A hat goes on your head.
Level 4 · Challenge
Challenge
Find the hidden rule.
1. Which is the odd one out? 4, 9, 16, 20
4, 9 and 16 are square numbers (2×2, 3×3, 4×4). 20 is not.
2. Which is the odd one out? bee, ant, spider, wasp
Bees, ants and wasps are insects with 6 legs. A spider has 8 legs and is not an insect.
3. Which is the odd one out? Monday, Tuesday, July, Friday
A Monday
B July
C Tuesday
D Friday
Monday, Tuesday and Friday are days of the week. July is a month.
Page 9 · Well done
You’ve finished Odd One Out
You can now solve odd-one-out puzzles by finding what most things share — the group rule — and spotting the one that breaks it. This is real detective thinking!
RememberFind what most of them have in common first. The odd one out is the one that doesn’t follow that group rule.
🎉Great work! Try another module next — every one helps you get ready.
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