Math Riddles for Kids
Math, in itself, is like a never-ending riddle, filled with layers of complexities and challenges. Every problem brings new concepts, formulas, and solutions to uncover. While maths does sharpen your mind, sometimes it tests our nerves and all we want is to close the book and go to sleep.
But don’t worry, we are going to introduce you to a new face of mathematics that you might have not seen before. Yes, you guessed it rightly, we have brought some intriguing math riddles that are anything but ordinary. These riddles are perfect for young learners looking to sharpen their thinking skills.
These riddles don’t require the usual formulas or calculations like your typical math problems and are very simple just like kids riddles that we shared before. All they need is a bit of focus and what we call general knowledge. Ready to put your brain to the test? Let’s dive into these math riddles for kids and see how many you can solve!
101 Math Riddles for Kids
Riddle: I am a number. When you multiply me by any number, the result is always the same. What number am I?
Zero.
Riddle: I am a three-digit number. My tens digit is five more than my ones digit, and my hundreds digit is eight less than my tens digit. What number am I?
194.
Riddle: How many sides does a triangle have?
3.
Riddle: What number is three times seven?
21.
Riddle: If I am three times as old as my son, and I am 36, how old is my son?
12.
Riddle: If you buy 7 packs of gum for 50 cents each, how much do you spend?
$3.50.
Riddle: What number do you get if you multiply all the fingers on one hand?
120 (1 × 2 × 3 × 4 × 5).
Riddle: How many months have 28 days?
All 12 months.
Riddle: What is the product of 12 and 6?
72.
Riddle: If you add 1 to me, I become an even number. What number am I?
Any odd number.
Riddle: You have two apples. You eat one. How many apples do you have now?
One.
Riddle: If you divide 30 by half and add 10, what do you get?
70 (30 ÷ 0.5 = 60, 60 + 10 = 70).
Riddle: What number is two less than a dozen?
10.
Riddle: I am an even number between 40 and 50, and the sum of my digits is 10. What number am I?
46.
Riddle: How many minutes are there in one and a half hours?
90 minutes.
Riddle: If there are 3 apples and you take away 2, how many apples do you have?
2 (because you took them).
Riddle: What is the sum of the angles in a triangle?
180 degrees.
Riddle: I am a multiple of 5, greater than 20 but less than 30. What number am I?
25.
Riddle: How many sides does a hexagon have?
6.
Riddle: If you count from 1 to 100, how many times do you pass the number 7?
20 times (7, 17, 27, 37, etc., and 70, 71, 72, etc.).
Riddle: I have four sides, but I’m not a square. What am I?
A rectangle.
Riddle: I am a two-digit number. My digits add up to 5, and I am a multiple of 5. What number am I?
23.
Riddle: What is half of a dozen?
6.
Riddle: If you double me and then add 3, you get 13. What number am I?
5.
Riddle: If 2 is company and 3 is a crowd, what is 4 and 5?
9.
Riddle: What is the next prime number after 7?
11.
Riddle: If you have 100 and take away 25 twice, how much do you have?
50.
Riddle: What is one-quarter of 40?
10.
Riddle: What number is both the square of a number and also a cube of a number?
64 (8^2 and 4^3).
Riddle: How many edges does a cube have?
12.
Riddle: Math Riddles for Adults There are 500 coffins and 500 men. The undertaker asks the first man to open every coffin, the second to close every second coffin, the third to toggle every third coffin, and so on. After all 500 men have done their task, how many coffins are left open?
22 coffins remain open (only those with square numbers remain open).
Riddle: In this sequence, we have numbers like 123=0, 4235=0, 656=2, 5390=2, and so on. Based on this pattern, what is 123456789?
0 (the riddle counts how many circles are in the digits).
Riddle: How do you go from 98 to 720 by changing just one letter?
Turn “98” into “nine” and change one letter to make it “one” (720 seconds = 12 minutes = noon).
Riddle: I am a number with a couple of friends. Quarter a dozen, and you’ll find me again. What am I?
Three.
Riddle: Add me to myself and multiply by four. Divide me by eight, and you will have me once more. What number am I?
Any number (mathematically, the operations cancel out).
Riddle: In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?
The person was born in 2005 B.C., so time is counted backward.
Riddle: There is a three-digit number. The second digit is four times the third digit, while the first digit is three less than the second digit. What is the number?
141.
Riddle: How many nines are there between 1 and 100?
20.
Riddle: “In two years, I will be twice as old as I was five years ago,” said Tom. How old is Tom?
Tom is 12 years old.
Riddle: What is half of two plus two?
3 (half of 2 is 1, and 1 + 2 = 3).
Riddle: Mom and dad have four daughters, and each daughter has one brother. How many people are in the family?
7 people (4 daughters, 1 brother, and the parents).
Riddle: Four years ago, Alex was twice as old as Jake. Four years from now, Jake will be three-quarters of Alex’s age. How old is Alex?
Alex is 12.
Riddle: If it’s two hours later, then it will take half as much time till midnight as it would if it were an hour later. What time is it now?
It’s 9 PM.
Riddle: Sally is 54 years old, and her mother is 80. How many years ago was Sally’s mother three times her age?
41 years ago (Sally was 13, and her mother was 39).
Riddle: If two hours ago, it was as long after one o’clock in the afternoon as it was before one o’clock in the morning, what time is it now?
11PM.
Riddle: I am four times as old as my daughter. In 20 years, I will be twice as old as her. How old are we now?
I am 40, and my daughter is 10.
Riddle: An apple is 40 cents, a banana is 60 cents, and a grapefruit is 80 cents. How much is a pear?
40 cents (the price is based on the number of vowels in the fruit’s name).
Riddle: If you’re 8 feet away from a door and with each move, you advance half the distance to the door, how many moves will it take to reach the door?
You will never completely reach the door (you get infinitely closer, but never quite there).
Riddle: In a bicycle race, the man who came two places in front of the last man finished one place ahead of the man who came fifth. How many contestants were there?
6 contestants.
Riddle: My daughter has as many sisters as she has brothers, and each of her brothers has twice as many sisters as brothers. How many sons and daughters do I have?
4 daughters and 3 sons.
Riddle: When my father was 31, I was 8. Now he is twice as old as me. How old am I?
You are 23.
Riddle: What did one math book say to the other?
“I have so many problems.”
Riddle: One brick weighs 1 kilogram and half a brick. How much does one brick weigh?
2 kilograms.
Riddle: Place three matches on a table. Add two more matches to make eight. How is this possible?
Arrange the matches to form the Roman numeral VIII (8).
Riddle: There are 25 red balls, 47 green balls, and 3 blue balls in a basket. A blind man needs to pick at least two balls of different colors. What is the minimum number of balls he has to pick?
48 balls (after picking 47 green balls, the next one must be a different color).
Riddle: Use the numbers 2, 3, 4, and 5, and the symbols + and = to create a true equation.
2 + 5 = 3 + 4.
Riddle: If you cut a cube into 27 smaller cubes, how many cuts do you make?
6 cuts.
Riddle: What number multiplied by itself gives the same result as adding the number to itself?
2
Riddle: Two fathers and two sons go fishing. They each catch one fish, yet only three fish are caught. How is this possible?
There are three people: a grandfather, father, and son.
Riddle: If I split $100 between three people so that one person gets twice as much as the second, and the second gets twice as much as the third, how much does each person get?
$57.14, $28.57, and $14.29.
Riddle: If you multiply me by any other number, the answer will always be zero. What number am I?
Zero.
Riddle: What number never ends, no matter how much you subtract?
Infinity.
Riddle: What is the smallest number greater than 0 that is divisible by both 5 and 10?
10.
Riddle: What is the next prime number after 7?
11.
Riddle: What happens when you add an odd number and an even number?
You always get an odd number.
Riddle: What time is it if the hour and minute hands form a straight line?
6:00.
Riddle: Which two numbers, when multiplied, give the same result as when added?
2 and 2.
Riddle: Two trains are traveling towards each other. One leaves the station at 7:00 AM, and the other leaves at 7:30 AM. They meet after 30 miles. What time did they meet?
8:00 AM.
Riddle: If you take away one from me, I remain even. What number am I?
Any even number.
Riddle: What is the result of dividing 30 by 1/2 and adding 10?
70 (30 ÷ 0.5 = 60, and 60 + 10 = 70).
Riddle: I am a two-digit number. My tens digit is five more than my ones digit, and my digits add up to 9. What number am I?
63.
Riddle: 15 Funny Math Riddles A math teacher was feeling cold, so she went and stood in the corner of the room. Why did she do that?
Because the corner is always 90 degrees!
Riddle: A mathematician, a physicist, and an engineer are walking together when they spot a black sheep. The physicist says, “All sheep are black!” The engineer says, “Some sheep are black!” What does the mathematician say?
“There is at least one sheep in this field that is black on one side.”
Riddle: If seven cats can catch seven mice in seven minutes, how long would it take one hundred cats to catch one hundred mice?
Seven minutes! Each cat catches one mouse in seven minutes.
Riddle: Why did the math student bring a ladder to class?
Because she wanted to reach the highest common factor!
Riddle: A boy walks into a candy store and sees a jar of 100 jellybeans. The store owner says, “For every jellybean you take, I’ll add 5 more.” The boy takes 10 jellybeans, and the jar is now empty. How is that possible?
Because the boy took all the jellybeans at once, and there were no more to add!
Riddle: A farmer counted 196 cows in the field, but when he rounded them up, he had 200. How is this possible?
Because when you round 196, it rounds up to 200!
Riddle: Why did the number 10 get in trouble during class?
Because it kept arguing with 1, saying, “You’re nothing without me!”
Riddle: Three people are splitting a pizza. The first person wants 1/2 of the pizza, the second wants 1/4, and the third wants 1/8. The pizza guy says, “I’ll cut it once, and you’ll all get your share.” How did he do it?
He cut it in a spiral, so everyone got their exact share.
Riddle: Why did the girl bring coins to her math test?
Because she wanted to be able to make some cents of the problems!
Riddle: Two cats are racing up a hill. One cat is named One-Two-Three, and the other is named Un-Two-Trois. Who wins the race?
One-Two-Three, because Un-Two-Trois quatre cinq!
Riddle: A man has 20 dogs and 10 cats. He sells half of his dogs and gives away half of his cats. How many legs do the remaining animals have in total?
60 legs (10 dogs with 40 legs + 5 cats with 20 legs).
Riddle: A mathematician walks into a bar and orders a beer. The bartender gives him a beer, and the mathematician says, “I’ll drink half of this, then half of the next half, and so on forever.” How many beers does the mathematician actually drink?
One beer in total, because the sum of the series 1/2 + 1/4 + 1/8… converges to 1!
Riddle: Why did the fraction break up with the decimal?
Because she found him too irrational!
Riddle: A teacher gives her student 15 apples and asks him to distribute them among 5 friends. The student gives each of his 5 friends 3 apples and says, “Mission accomplished!” The teacher is confused and says, “But you didn’t follow my instructions!” What was the student’s reply?
“I gave each friend 3 apples, which is distributing them, just not equally!”
Riddle: A math teacher tells his students, “You can’t have your cake and eat it too.” A student asks, “But if I divide the cake infinitely, I can eat it forever, right?” What does the teacher say?
“No matter how you slice it, it’s still a finite cake!”
Riddle: 15 Challenging Riddles for Adults You have a 3-gallon jug and a 5-gallon jug. How can you measure exactly 4 gallons of water using these two jugs?
Fill the 5-gallon jug and pour it into the 3-gallon jug until it’s full. This leaves 2 gallons in the 5-gallon jug. Empty the 3-gallon jug, then pour the remaining 2 gallons from the 5-gallon jug into the 3-gallon jug. Fill the 5-gallon jug again and pour it into the 3-gallon jug until it’s full. Now you have exactly 4 gallons left in the 5-gallon jug.
Riddle: A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
The ball costs 5 cents. If the ball costs x, then the bat costs x + $1.00. Together, they cost $1.10, so x + (x + 1.00) = 1.10. Solving this, x = $0.05.
Riddle: If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
It would take 5 minutes. Each machine makes 1 widget in 5 minutes, so 100 machines would make 100 widgets in the same time.
Riddle: You are given 12 identical-looking balls, but one is either heavier or lighter. You also have a balance scale. What is the fewest number of weighings needed to find the odd ball and whether it’s heavier or lighter?
3 weighings. Split the balls into 3 groups of 4 and weigh them. Continue narrowing down until you isolate the odd one out.
Riddle: A man buys a horse for $60, sells it for $70, buys it back for $80, and sells it again for $90. How much money did he make or lose?
He made $20. The man netted $10 in the first transaction and another $10 in the second, for a total of $20 profit.
Riddle: A man gave one son 10 cents and another son was given 15 cents. What time is it?
1:25 (a play on words; “one was given” sounds like 1:15, and adding 10 minutes makes it 1:25).
Riddle: A car is traveling 60 miles per hour. How long will it take for the car to travel 60 miles?
1 hour.
Riddle: If you have two ropes, each of which takes exactly one hour to burn, but they burn at uneven rates, how do you measure 45 minutes?
Light one rope at both ends and the other at one end. The first rope will take 30 minutes to burn, and when it’s finished, light the second end of the second rope. It will take 15 minutes more to burn completely, giving you 45 minutes.
Riddle: A box contains 12 balls, of which some are black and the rest are white. The total number of ways to choose 3 balls from the box is 220. How many black balls are there in the box?
8 black balls. The number of ways to choose 3 balls can be written as (xC3 + (12-x)C3 = 220), solving this equation gives x = 8.
Riddle: Three people check into a hotel room that costs $30. They each contribute $10. The manager realizes there’s a discount and the room costs only $25, so he gives $5 to the bellboy to return to the guests. The bellboy gives $1 to each person and keeps $2 for himself. Now each guest has paid $9, making $27 in total. The bellboy kept $2, making $29. Where is the missing dollar?
There’s no missing dollar. The $27 already includes the bellboy’s $2. The correct breakdown is $25 for the room and $2 for the bellboy, which equals $27.
Riddle: You have two hourglasses, one measuring 7 minutes and the other measuring 4 minutes. How can you measure exactly 9 minutes using both?
Start both hourglasses at the same time. When the 4-minute hourglass runs out, flip it. When the 7-minute hourglass runs out, flip it. When the 4-minute hourglass runs out again (after 8 minutes), the 7-minute hourglass will have 1 minute left. Let that run out to measure exactly 9 minutes.
Riddle: A man has 53 socks in his drawer: 21 identical blue, 15 identical black, and 17 identical white. The lights are out, and he is completely in the dark. How many socks must he take out to be sure he has a matching pair?
4 socks. In the worst case, he could pull out one of each color (3 socks), but the next sock must match one of the previous ones.
Riddle: You are on a game show and given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what’s behind the doors, opens another door, say No. 3, which has a goat. He then says to you, “Do you want to switch to door No. 2?” Is it to your advantage to switch?
Yes, you should switch. Initially, you had a 1/3 chance of picking the car and a 2/3 chance of picking a goat. After the host reveals a goat, the probability of the car being behind the other door is 2/3, making it advantageous to switch.
Riddle: How can you place exactly 10 apples into 5 baskets so that each basket contains an odd number of apples?
Place 1 apple in each of the first 4 baskets, and 6 apples in the fifth basket (which contains the other baskets).
Riddle: A father is twice as old as his son. Four years ago, the father was three times as old as his son. How old are they now?
The son is 8, and the father is 16. Solving the system of equations based on their ages gives this result.