47 brain teasers for kids with answers
Short number, order and word puzzles with explanations. Work on paper or read them aloud.
Updated
Questions 1–20
An arithmetic sequence starts 7, 11, 15, 19. Continue it by one term.
easy
23. Add 4 each time.
The consecutive differences are 4, 4, and 4, so 19 + 4 = 23.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Supply the next term of the arithmetic sequence 42, 37, 32, 27.
easy
22. Subtract 5 each time.
Each term is 5 less than the previous term, so 27 - 5 = 22.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Extend the geometric sequence 3, 9, 27, 81 by one term.
easy
243. Multiply by 3 each time.
Each term divided by the previous term is 3, so 81 x 3 = 243.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
A geometric sequence with positive terms reads 160, 80, 40, 20. Which term is next?
easy
10. Divide by 2 each time.
Each term is half the previous term, and half of 20 is 10.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Starting with 2 and 3, each new term is the sum of the previous two. What follows 2, 3, 5, 8, 13?
easy
21.
The previous two terms are 8 and 13, and 8 + 13 = 21.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Advance three months at a time from February to May to August to November. Name the next month.
easy
February.
Three months after November is February of the next year.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Perfect squares begin 1, 4, 9, 16, 25. Supply the sixth term.
easy
36.
The terms are 1 squared, 2 squared, 3 squared, 4 squared, and 5 squared. The sixth term is 6 squared, which is 36.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Reading the prime numbers in order gives 2, 3, 5, 7, 11. Which number follows?
easy
13.
The integer after 11 is 12, which has factors other than 1 and itself. The next integer, 13, has only 1 and 13 as positive factors.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
Cubes appear in order as 1, 8, 27, 64. Name the next cube.
easy
125.
The terms are 1 cubed through 4 cubed. The next is 5 cubed = 5 x 5 x 5 = 125.
Source: OpenStax, College Algebra 2e, Sequences https://openstax.org/books/college-algebra-2e/pages/9-1-sequences-and-their-notations
A bus leaves at 9:35 a.m. and travels for 2 hours 45 minutes. What is its arrival time?
easy
12:20 p.m.
9:35 plus 2 hours is 11:35, and another 45 minutes is 12:20.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
Socks come in four colors. Without looking, how many socks guarantee that two share a color?
easy
Five socks.
The first four socks could all differ. A fifth must match one of those four colors.
Source: OpenStax, College Algebra, Counting Principles https://openstax.org/books/college-algebra/pages/9-5-counting-principles
Thirteen people record only their birth month. What must be true?
easy
At least two people recorded the same month.
Twelve labels cannot hold 13 records with at most one record per label.
Source: OpenStax, College Algebra, Counting Principles https://openstax.org/books/college-algebra/pages/9-5-counting-principles
Every amber token is round, and no round token is wooden. Could an amber token be wooden?
easy
No.
Amber implies round, and round excludes wooden, so amber excludes wooden.
Source: Open Logic Project, forall x: Calgary https://forallx.openlogicproject.org/html/Ch11.html
Some poets are cyclists, and all cyclists wear helmets. What follows about the poets who are cyclists?
easy
Those poets wear helmets.
Every member of the cyclist set wears a helmet, including the poets in that set.
Source: Open Logic Project, forall x: Calgary https://forallx.openlogicproject.org/html/Ch11.html
You pass the runner currently in second place. Which place do you now hold?
easy
Second place.
Passing the second-place runner puts you in that runner's former position.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
One match is available beside a candle, a lantern, and a fireplace. What must be lit first?
easy
The match.
The match must be burning before it can light any listed object.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
Rearrange LISTEN into a word associated with quiet.
easy
SILENT.
LISTEN and SILENT each contain E, I, L, N, S, and T exactly once.
Source: Merriam-Webster.com Dictionary, "silent" https://www.merriam-webster.com/dictionary/silent
The letters of EARTH can name a body organ. Name it.
easy
HEART.
EARTH and HEART use the same letters: A, E, H, R, and T.
Source: Merriam-Webster.com Dictionary, "heart" https://www.merriam-webster.com/dictionary/heart
Turn COLD into a precious metal by changing one letter.
easy
GOLD.
Replacing C with G changes COLD to GOLD.
Source: Merriam-Webster.com Dictionary, "gold" https://www.merriam-webster.com/dictionary/gold
A one-letter change turns MOUSE into a building. Which word results?
easy
HOUSE.
Replacing M with H changes MOUSE to HOUSE.
Source: Merriam-Webster.com Dictionary, "house" https://www.merriam-webster.com/dictionary/house
Questions 21–40
Delete the first letter of PLANE to name a narrow road.
easy
LANE.
PLANE without its first letter P is LANE.
Source: Merriam-Webster.com Dictionary, "lane" https://www.merriam-webster.com/dictionary/lane
From TRAIN remove one letter to get precipitation.
easy
RAIN.
Removing T from TRAIN leaves RAIN.
Source: Merriam-Webster.com Dictionary, "rain" https://www.merriam-webster.com/dictionary/rain
Insert one letter into PLAN to make a flying vehicle.
easy
PLANE.
Adding E after PLAN produces PLANE.
Source: Merriam-Webster.com Dictionary, "plane" https://www.merriam-webster.com/dictionary/plane
Which letter can be added to STAR to mean the beginning of something?
easy
Add T to make START.
Appending T to STAR spells START.
Source: Merriam-Webster.com Dictionary, "start" https://www.merriam-webster.com/dictionary/start
Tooth, hair, and paint share which following word?
easy
BRUSH: toothbrush, hairbrush, and paintbrush.
Appending BRUSH forms TOOTHBRUSH, HAIRBRUSH, and PAINTBRUSH.
Source: Merriam-Webster.com Dictionary, "toothbrush" https://www.merriam-webster.com/dictionary/toothbrush
An animal is hidden in eduCATION. Which one?
easy
CAT.
eduCATION contains C, A, T consecutively.
Source: Merriam-Webster.com Dictionary, "cat" https://www.merriam-webster.com/dictionary/cat
Decode alphabet positions 8-5-1-20 as a word.
easy
HEAT.
Alphabet positions 8, 5, 1, and 20 are H, E, A, and T.
Source: Merriam-Webster.com Dictionary, "heat" https://www.merriam-webster.com/dictionary/heat
Using A=1 through Z=26, what word is 13-1-16?
easy
MAP.
Alphabet positions 13, 1, and 16 are M, A, and P.
Source: Merriam-Webster.com Dictionary, "map" https://www.merriam-webster.com/dictionary/map
Rearrange BELOW to name a joint in the arm.
easy
ELBOW.
BELOW and ELBOW each contain B, E, L, O, and W exactly once.
Source: Merriam-Webster.com Dictionary, "elbow" https://www.merriam-webster.com/dictionary/elbow
Reverse DRAW to name an area in a hospital.
easy
WARD.
Reading the letters D-R-A-W from right to left gives W-A-R-D.
Source: Merriam-Webster.com Dictionary, "ward" https://www.merriam-webster.com/dictionary/ward
Take the first letters of Bright Owls Observe Keenly. What word appears?
easy
BOOK.
The initial letters of Bright, Owls, Observe, and Keenly are B, O, O, and K.
Source: Merriam-Webster.com Dictionary, "book" https://www.merriam-webster.com/dictionary/book
A word meaning to observe sounds like a large body of salt water. Give both spellings.
easy
SEE and SEA.
SEE means to perceive or observe, while SEA names a large body of salt water; both are pronounced the same way.
Source: Merriam-Webster.com Dictionary, "see" https://www.merriam-webster.com/dictionary/see
Choose one of 3 shirts, one of 4 pairs of trousers, and one of 2 hats. How many outfits are possible?
easy
24 outfits.
The multiplication principle gives 3 x 4 x 2 = 24.
Source: OpenStax, College Algebra, Counting Principles https://openstax.org/books/college-algebra/pages/9-5-counting-principles
A recipe uses 240 grams of flour for 6 muffins. At the same rate, how much flour makes 15 muffins?
easy
600 grams.
240 / 6 = 40 grams per muffin, and 40 x 15 = 600 grams.
Source: OpenStax, Prealgebra 2e, Proportions https://openstax.org/books/prealgebra-2e/pages/6-5-solve-proportions-and-their-applications
On a map, 3 centimeters represents 12 kilometers. What distance does 8 centimeters represent?
easy
32 kilometers.
12 / 3 = 4 kilometers per centimeter, and 8 x 4 = 32 kilometers.
Source: OpenStax, Prealgebra 2e, Proportions https://openstax.org/books/prealgebra-2e/pages/6-5-solve-proportions-and-their-applications
Triple a number and add 4 to get 31. What is the number?
easy
9.
3x + 4 = 31, so 3x = 27 and x = 9.
Source: OpenStax, Prealgebra 2e, Solving Equations https://openstax.org/books/prealgebra-2e/pages/8-1-solve-equations-using-the-subtraction-and-addition-properties-of-equality
A rectangle has perimeter 38 units and length 12 units. Find its width.
easy
7 units.
2 x (12 + width) = 38, so 12 + width = 19 and the width is 7.
Source: OpenStax, Prealgebra 2e, Rectangles, Triangles, and Trapezoids https://openstax.org/books/prealgebra-2e/pages/9-4-use-properties-of-rectangles-triangles-and-trapezoids
The base of a triangle is 14 units and its perpendicular height is 9 units. What is its area?
easy
63 square units.
Triangle area is one-half x base x height, so 14 x 9 / 2 = 63.
Source: OpenStax, Prealgebra 2e, Rectangles, Triangles, and Trapezoids https://openstax.org/books/prealgebra-2e/pages/9-4-use-properties-of-rectangles-triangles-and-trapezoids
A bag holds 5 red, 3 blue, and 2 green counters. What is the probability of drawing green once?
easy
1/5.
There are 2 green counters among 10 total, and 2/10 simplifies to 1/5.
Source: OpenStax, Prealgebra 2e, Averages and Probability https://openstax.org/books/prealgebra-2e/pages/5-5-averages-and-probability
Uma finishes before Rae, Rae before Sol, and Sol before Tia. Who finishes first?
easy
Uma.
The clues form the order Uma, Rae, Sol, Tia.
Source: Open Logic Project, forall x: Calgary https://forallx.openlogicproject.org/html/Ch11.html
Questions 41–47
Dena is taller than Eli. Farah is shorter than Dena but taller than Eli. Order them from tallest to shortest.
easy
Dena, Farah, Eli.
Dena is above both others, and Farah is explicitly above Eli.
Source: Open Logic Project, forall x: Calgary https://forallx.openlogicproject.org/html/Ch11.html
Four lockers stand left to right. P is at the far left, Q is immediately right of P, and S is at the far right. Where is R?
easy
Third from the left.
P occupies 1, Q occupies 2, and S occupies 4, leaving position 3 for R.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
Art, music, and science talks occur at 1, 2, and 3 o'clock, one per hour. Science is at 3, and art is before music. When is music?
easy
2 o'clock.
With science at 3, art and music occupy 1 and 2. Art must be earlier, so music is at 2.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
A code replaces each letter with the next letter of the alphabet. Decode DBU.
easy
CAT.
Moving D, B, and U back one letter gives C, A, and T.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
Box A contains the key to B, B contains the key to C, and C holds the prize. Which box must be opened first?
easy
Box A.
Opening B requires A's key, and opening C requires B's key, so A must precede both.
Source: Open Logic Project, forall x: Calgary https://forallx.openlogicproject.org/html/Ch11.html
A three-digit password has a first digit twice its second and a third digit one less than its second. The second digit is 3. What is the password?
easy
632.
Twice 3 is 6, and one less than 3 is 2.
Source: OpenStax, Prealgebra 2e, Solving Equations https://openstax.org/books/prealgebra-2e/pages/8-1-solve-equations-using-the-subtraction-and-addition-properties-of-equality
A meeting is after Monday but before Thursday, and it is not on Wednesday. Which day is it?
easy
Tuesday.
The days after Monday and before Thursday are Tuesday and Wednesday; excluding Wednesday leaves Tuesday.
Source: NRICH, Using NRICH Tasks to Develop Key Problem-Solving Skills https://nrich.maths.org/articles/using-nrich-tasks-develop-key-problem-solving-skills
Plan the round and team scores
8 turns × 60 seconds = 8 minutes of play, plus instructions and breaks.
60
These are adjustable house rules. Pause whenever the group needs more time.
Team 1: 0
Team 2: 0
Use this set with a group
Read a prompt, allow thinking time, then invite an answer or a pass. For a timed round, choose a turn length before starting. A host can keep the printed answers out of view until the round ends.