Thirty brain teasers for children from six: number sequences, logic, arithmetic and ordering, with answers that fold out. Easiest first, hardest last. All can be solved in your head, and almost all get easier if you draw them.
Brain teasers are maths that does not look like maths. A child who refuses to do sums in the workbook will happily work out how many ducks there are, because there is an adult thinking alongside them and because there is an answer to be found. Here are the thirty our nannies keep up their sleeve, for the car, the waiting room and the dinner table.
The waiting room at the vårdcentral (local health centre) in Jakobsberg, a Thursday at three. An eight-year-old and his nanny have twenty minutes to go and the phone is in the bag. ”Which number comes next: 2, 4, 8, 16?” He thinks, counts on his fingers, says 32 and wants another. By the time they are called in he has solved six and made up one of his own that the nanny could not crack. That is how brain teasers work: all they need is an adult willing to wait.
Thirty brain teasers
- Which number comes next: 2, 4, 8, 16?
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32. Each number is double the one before.
- Which number comes next: 1, 1, 2, 3, 5, 8?
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13. Each number is the sum of the two before it.
- One duck walks in front of two ducks, one duck walks behind two ducks, and one duck walks in the middle. How many ducks are there?
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Three.
- If you overtake the runner in second place in a race, what place are you in?
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Second place. You took second place, not first.
- Can you overtake the runner who is last in a race?
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No. If you overtook the last runner, you were last yourself, so it was not the last runner you overtook.
- What is double half of ten?
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Ten.
- How many times can you subtract five from twenty-five?
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Once. After that it is twenty.
- What comes next in the row: Monday, Wednesday, Friday?
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Sunday. Every other day.
- Three children share a pizza with eight slices. Everyone gets the same number of whole slices, and there are slices left over. How many does each child get?
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Two each, with two slices left over.
- I have three apples and give away two. Then I get three more. How many do I have?
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Four.
- A week has seven days. How many days are there in three weeks and two days?
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23.
- Which weighs more: a kilo of flour or a thousand grams of sugar?
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The same. A thousand grams is a kilo.
- A clock shows quarter past three. Roughly how many degrees are there between the hands?
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About seven degrees. The hour hand has moved a quarter of an hour past the three.
- If yesterday was Sunday, what day is it the day after tomorrow?
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Wednesday.
- How many triangles does a pyramid with a square base have?
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Four. The base is a square.
- Which number fits: 3, 6, 9, 12, ?
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15. The three times table.
- Lisa is older than Kalle. Kalle is older than Sara. Who is the youngest?
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Sara.
- Four children shake hands with each other, everyone with everyone, once. How many handshakes is that?
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Six.
- What is half of half of 100?
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25.
- A train is 100 metres long and travels 100 metres. How far has the back of the train moved?
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100 metres. The whole train moves the same distance.
- Which letter comes next: A, C, E, G?
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I. Every other letter.
- If three cats catch three mice in three minutes, how many mice do nine cats catch in three minutes?
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Nine.
- I am thinking of a number. If I add five and take away three, I get ten. Which number?
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Eight.
- How many legs do three dogs and two hens have altogether?
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Sixteen. Twelve and four.
- Which number fits: 10, 8, 6, 4, ?
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2.
- A farmer has four fields and puts two sheep in each. Then he sells three sheep. How many does he have left?
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Five.
- A mother has four daughters. Each daughter has one brother. How many children does the mother have?
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Five. The daughters share the same brother.
- What is 99 plus 1 minus 100?
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Zero.
- Which shape has the most corners: a triangle, a square or a circle?
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The square, four. The circle has none.
- If you turn the digit 6 upside down, which number do you get?
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9.
How to make them work
- Draw. Paper and pencil solve the ducks, the handshakes and the sheep.
- Wait. A minute of silence is thinking, not failing.
- Wrong answers are good answers. Ask how your child was thinking. It is usually almost right.
- Let your child make up their own. Number sequences are the easiest: your child decides the rule, you guess.
- Stop while it is still fun. Three brain teasers, then a break. A child who gets seven in a row stops thinking and starts guessing.
Which brain teasers for which age?
| Age | What your child can manage | Examples from the list |
|---|---|---|
| 5 to 6 years | Counting objects and simple quantities, ideally with something to point at | The ducks, the apples, half of ten, the legs on dogs and hens |
| 7 to 8 years | Number sequences with one rule, days of the week, double and half | 2, 4, 8, 16; Monday, Wednesday, Friday; yesterday was Sunday |
| 9 to 10 years | Two conditions at once, ordering, trick questions about the race | Lisa, Kalle and Sara; overtaking second place; the mother with four daughters |
| 11 to 12 years | Arithmetic in several steps and teasers that fool adults too | The 100-metre train, the handshakes, the cats and the mice |
Four kinds of brain teaser, and the trick for each
Number sequences have a rule to be found: double, add three, skip one. The trick is to look at the difference between two numbers at a time. If the difference is the same all the way, the rule is addition; if it grows, it is multiplication. Children from seven understand this if you draw the numbers in a row and write the difference underneath.
Ordering puzzles are about who is oldest, who is in front and what comes after. The trick is a line on a piece of paper: Lisa on the far left, Sara on the far right. Drawn, it takes ten seconds; in the head, even adults often get it wrong.
Arithmetic puzzles look like the maths book but have a twist. How many times can you subtract five from twenty-five? Once, after that it is no longer twenty-five. The trick is to read the question one more time and ask: what does it actually want to know?
Trick puzzles are the ones built on an assumption. The farmer with the sheep, the race where you overtake second place, the mother with four daughters. The trick is to say the assumption out loud afterwards: we thought each daughter had a brother of her own. That habit is what lets your child crack the next trick puzzle on their own.
Make your own brain teasers at home
Number sequences are the easiest to invent: your child secretly picks a rule, writes four numbers on a slip of paper, and you have to guess the fifth. The next step is number stories about the family: if there are four of us and everyone shakes hands with everyone, how many handshakes is that? And on the way home: if we see three dogs and two cats, how many legs? A child who makes up their own brain teasers has understood something that cannot be taught, namely that a problem is something you build, not something that only comes from a book.
If you want more, there are 100 riddles for kids with answers, sorted by age with ten number riddles at the end, and Riddles that work for both adults and children with the bat and the ball, which is the brain teaser that fools the most adults.
How we do it with our families
The walk home from fritids (after-school care) is brain teaser time. Three of them, then three from the child. Sanna has a nine-year-old in Bromma on Mondays and Wednesdays, and because it is the same nanny every week she knows that this nine-year-old wants number sequences, not ducks. She keeps a little note on her phone of which ones are used up, because he remembers every single one and says ”we've had that one” otherwise. When he got stuck on the handshakes last week she drew four dots on a napkin at the café by the square and drew lines between them. Six lines. He looked at the napkin for ten seconds and said he wanted one with five children next time.
Would you like a nanny who comes on the same days every week and whom your children know? Book a free first meeting with the nanny in your home, and we will work out a plan around your hours.
Read more: 100 riddles for kids with answers, sorted by age · Riddles that work for both adults and children · Quiz questions for kids · FAQ
Frequently asked questions
What is the difference between brain teasers and riddles?
Riddles play with words and meanings: what has teeth but cannot bite? Brain teasers are logic and arithmetic: numbers in a row, ordering, quantities and what comes next. Children who like maths like brain teasers, children who like language like riddles, and most like both if they get them in the right order and at the right age.
From what age do brain teasers work?
From six, when your child counts to a hundred and understands before and after. The easiest ones, such as the ducks and double half of ten, work from five. The number sequences are for seven to eight and up, and the ones that require holding three conditions in your head, such as Lisa, Kalle and Sara, suit children from nine.
How do you help without giving the answer?
Ask what your child already knows, and ask them to draw. Three ducks on a piece of paper, four children shaking hands, a timeline for the tablets. Almost every brain teaser solves itself once it is drawn. If your child gives a wrong answer, ask how they were thinking. The thinking is usually almost right, and then a single follow-up question is enough to get there.
Are brain teasers good for maths at school?
Yes, in a way the textbook is not always. A brain teaser trains your child to read a problem carefully, find what is actually being asked and try an idea without being afraid of getting it wrong. That is exactly the skill needed for word problems in years three and four, where many children who are good at sums still get stuck.
Are there more brain teasers?
Our collection of a hundred riddles has ten number and logic riddles at the end, and the quiz for children has arithmetic questions in levels two and three. The riddles for adults and children have the bat and the ball, the machines and the tablets, which are brain teasers for children from eleven and up. The best ones are still the ones your child makes up.