100 Best Number Riddles to Test Your Math Skills
Number riddles are one of the more difficult types of riddles. Stop and think, go step by step, and keep in mind that the answer could be a clever play on words or have an unusual twist.
Were you aware that there are contests for number riddles that take place to test your intelligence? Many people lose their minds while solving math riddles.
Math is a part of all of our lives, from adult math (calculating when to start cooking if the turkey takes 13 minutes per pound and the guests arrive at 2 p.m.) to Sudoku puzzles.
Here are some number riddles with answers that you might find interesting, and if you are unable to calculate the answer, you will be able to find the solution.
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Table of Contents
Best Number Riddles
If you don’t choose the best number brain teasers, they can be tedious. Where is 99 greater than 100? A microwave oven. One of the examples from the category of best number riddles.
1. What is the maximum possible number of times you can subtract number 5 from number 25?
Answer: Only once. This is because when you subtract 5 from 25 for the first time, it becomes number 20, then 15, and so on.
2. If a hen and a half lay an egg and a half in a day and a half, how many eggs will half a dozen hens lay in half a dozen days?
Answer: Two dozen. If you increase both the number of hens and the amount of time available four-fold (i.e., 1.5 times 4 equals 6), the number of eggs increases 16 times. 16 x 1.5 = 24.
3. 20 + 20 + 20=60. How can you make 60 again by using the same number 3 times, but it can’t be 20?
Answer: Use the number 5 three times, 55 + 5 = 60.
4. What two-digit numbers are each equal to their right-most digit squared?
Answer: 25 = 5² and 36 = 6².
5. Old Granny Adams left half her money to her granddaughter and half that amount to her grandson. She left a sixth to her brother, and the remainder, $1,000, to the dogs’ home. How much did she leave altogether?
Answer: She left $12,000. One half plus one quarter plus one-sixth equals eleven-twelfths. So, the remainder, $1,000, is one-twelfth of the whole, which must have been $12,000.
6. The sum total of the age of a mother and daughter is 66. The mother’s age is the daughter’s age reversed. There could be three different possibilities to this riddles’ answer. What would be their ages?
Answer: (51 + 15= 66), (42 + 24=66), or (60 + 06 =66).
7. What is x? 1 + 4 = 5; 2 + 5 = 12; 3 + 6 = 21; 8 + 11 = x
Answer: x = 96; (a + b) to (a + ab).
8. What is the only self-enumerating number in English?
Answer: Four. The number four has four letters, making it self-enumerating.
9. There are 100 pairs of dogs in a zoo. Two pairs of babies are born for every dog. Unfortunately, 23 of the dogs have not survived. How many dogs would be left in total?
Answer: 977 dogs (100 x 2 = 200; 200 + 800 = 1000; 1000 – 23 = 977).
Funny Number Riddles
What if math number puzzles were super entertaining? For example, how did the soccer fan know the score would be 0-0 before the game? Before each tournament, the score is always 0-0. An example is under the heading of funny number riddles.
1. A horse was tied to a rope 5 meters long and the horse’s food was 15 meters away from the horse. How did the horse reach the food?
Answer: The rope wasn’t tied to anything so he could reach the food.
2. If two’s company and three’s a crowd, what are four and five?
Answer: 9.
3. Double the number and then multiply the number by 4. Divide the outcome by 8, and you will get the initial once more. What number is it?
Answer: Any number, when a number is doubled and multiplied by 4 and divided by 8, the answer is the original number.
4. Which is correct: 18 plus 19 is 36 or, 18 plus 19 are 36?
Answer: Both are incorrect because 18 + 19 = 37.
5. Suppose you have six oranges and six melons in your right hand and 24 apples and eight watermelons in your left hand. What do you have?
Answer: You have such big hands!
6. Did you hear about the mathematician who is afraid of negative numbers?
Answer: He will stop at nothing to avoid them.
7. Do you know why the two 4s didn’t go to the cafeteria for lunch?
Answer: They already 8!
8. What do prime numbers and stoners have in common?
Answer: The higher they are, the more spaced out they get.
9. There is an empty container, and it has a diameter of one foot. How many total numbers of oranges can be put in this empty container?
Answer: One, the moment you place one orange, the container is not empty anymore.
10. What is the solution to any equation?
Answer: Multiply both sides by zero.
Easy Number Riddles
If you’re wondering how to tutor your child in simple arithmetic, start with easy number riddles. What, for example, did the triangle say to the circle? You’re useless. You can begin slowly and gradually enhance the strength of puzzles.
1. When Miguel was 6 years old, his little sister, Leila, was half is age. If Miguel is 40 years old today, how old is Leila?
Answer: She is 37 years old.
2. If you multiply this number by any other number, the answer will always be the same. What number is this?
Answer: Zero.
3. What two whole, positive numbers have the same answer when multiplied together as when added together?
Answer: 2 and 2.
4. If there are four apples and you take away three, how many do you have?
Answer: You took three apples, so you have three!
5. This one-digit number is more than 3 and less than 9. It is the number of sides in 2 triangles. Can you find out the number?
Answer: 6.
6. Jess’s pencil was wearing out and is now only three centimeters long. Her friend Stan’s new pencil was eight times that length. How long was Stan’s pencil?
Answer: 8 x 3 = 24 cms.
7. This number can be positive or negative, and it starts with I and ends with R. What is this number?
Answer: It’s an integer.
8. A cellphone and a phone case cost $110 in total. The cell phone costs $100 more than the phone case. How much was the cellphone?
Answer: $105 (not $110).
9. It is a 2 digit number, with the same digit in both ones and tens place. The digits added twice results in a ten. What is the number?
Answer: 55.
10. Amy has as many apples as there are months in a year. How many apples does she have?
Answer: 12 apples.
Hard Number Riddles
A math quiz can show how hard number riddles can be. For illustration, how many apples do you have if you have four and take three aside? You now have three apples since you got three!
1. Leonard works at the aquarium. When he tries to put each turtle in its own tank, he has one turtle too many. But if he puts two turtles per tank, he has one tank too many. How many turtles and how many tanks does Leonard have?
Answer: He has 3 tanks and 4 turtles.
2. Double my number, I’m less than a score, Half of my number is less than four. Add one to my double when bakers are near, Days of the week are still greater, I fear.
Answer: Six.
3. I am a three-digit number. My second digit is 4 times bigger than the third digit. My first digit is 3 less than my second digit. Who am I?
Answer: 141.
4. What is the highest number that can be written with three digits?
Answer: (9⁹)⁹ = 9³⁸⁷⁴²⁰⁴⁸⁹, which is a number with more than 369 million digits.
5. A small number of cards has been lost from a complete pack. If I deal among four people, three cards remain. If I deal among three people, two remain and if I deal among five people, two cards remain. How many cards are there?
Answer: There are 47 cards.
6. If 9999 = 4, 8888 = 8, 1816 = 6, 1212 = 0, then 1919 =
Answer: 4; 9999 has 4 closed areas (the top of the ‘9’). 8888 has 8 closed areas, the top and bottom parts of the 8 and there are no other digits. 1816 has 3 closed areas, (top and bottom of 8 and bottom of 6, and it has 2 other digits (3 * 2 = 6)). 1212 has 0 closed areas, (0 * 4 = 0).
7. This is a 5 digit number; when the last three digits are added, the answer is 0, the digit at the one’s place is the smallest odd number, the digit at the ten thousand places is the product of 4 and 2. What is the number?
Answer: 8 1 000.
8. What should you add to 55,555 to make it equal 500?
Answer: The minus sign. Place minus (-) between 555 and 55 to make this equation: 555 – 55 = 500.
9. Write down the next number in the pattern: 2, 3, 5, 8, 13…
Answer: 21.
10. My twin lives at the reverse of my house number. The difference between our house numbers ends in two. What are the lowest possible numbers of our house numbers?
Answer: The lowest possible numbers for the houses are 19 and 91. The difference is 72.
Tricky Number Riddles
Tricky number riddles can leave you scratching your head. I am, for example, a three-digit number. My second digit is four times larger than my third. My first digit is three digits lower than my second. 141.
1. I am a three-digit number. My tens digit is six more than my ones digit. My hundreds digit is eight less than my tens digit. What number am I?
Answer: 193.
2. If you divide thirty by half, and add ten, what do you get?
Answer: 70.
3. Which one has two zero and two four? A) 004 B) 2024 C) 0024 D) 2024
Answer: When you pronounce a number say, 3006, it is pronounced as three thousand six. But, it is not pronounced as three two zero and six. Because, it will result in 3206. It might be grammatically but mathematically wrong or vice versa. The pronunciation does not say how many but what the number is at the particular position. Hence, 2024 has two zero and two four.
4. You are given 3 positive numbers. You can add these numbers and multiply them together. The result you get will be the same. Which are the numbers?
Answer: 1, 2 and 3.
5. Place three matches on a table. Tell a friend to add two more matches to make eight.
Answer: Add two matches to make a roman numeral eight.
6. Can you find a way in which you get 23 using only the number 2?
Answer: Use fractions, 22+2/2=23.
7. If 100 is divided by half. What would be the result?
Answer: 100÷1/2 = 100×2/1= 200.
8. Can you make 24 from the numbers 3, 3, 8, and 8? You can only use the operations + – x / (). You have to use all four numbers.
Answer: 8 / (3 – 8/3) = 24.
9. What is the product if you multiply all numbers on a phone’s dial pad?
Answer: It’s zero. Since the phone dial pad ends with a zero, multiplying anything by zero equals zero.
10. Using only addition, add eight 8s to get the number 1,000.
Answer: 888 + 88 + 8 + 8 + 8 = 1,000. First, get as close to 1,000 as you can (888). From there, it’s easy to figure out the rest.
Challenging Number Riddles
Solving challenging number riddles can either make you a genius or feel stupid. For example, if X is an odd number, removing a letter from X makes it even. What is the number? Seven (Seven-S=Even).
1. If seven people meet each other, and each shakes hands only once with each of the others, how many handshakes will there have been?
Answer: Twenty-one.
2. Among those numbers whose literal representation in capital letters consist only of straight line segments (for example, FIVE), only one number has a value equal to the number of segments used to write it. What is the number?
Answer: 29.
3. In an odd little town, there was an odd little stream, WIth odd little fish in an odd little team. A stranger approached a local fisherman, And asked him how much his odd little fish weighed. The odd little man replied: All the fish in this stream weigh exactly 1/2 of a pound plus 1/2 of a fish. Isn’t that odd? How many pounds does an odd little fish weigh?
Answer: One.
4. What is the smallest whole number that is equal to seven times the sum of its digits?
Answer: The answer to this math riddle is 21. You probably just guessed to answer this math riddle, which is fine, but you can also work it out algebraically. The two-digit number ab stands for 10a + b since the first digit represents 10s and the second represents units. If 10a + b = 7(a + b), then 10a + b = 7a + 7b, and so 3a = 6b, or, more simply, a = 2b. That is, the second digit must be twice the first. The smallest such number is 21.
5. In a certain country ½ of 5 = 3. If the same proportion holds, what is the value of 1/3 of 10?
Answer: 4.
6. I have a calculator that can display ten digits. How many different ten-digit numbers can I type using just the 0-9 keys once each, and moving from one keypress to the next using the knight’s move in chess? (In chess, the knight moves in an L shape: one square up and two across, two squares down and one across, two squares up and one across, and other like combinations.)
Answer: You can form the numbers 5034927618 and 5038167294. You can also form their reverses: 8167294305 and 4927618305. Hence four different numbers can be made. The key point is to realize that the number must start or end on the “5” key, followed/preceded by the ‘0’ key, otherwise, there is no way of using all ten keys during the route.
7. A snail is at the bottom of a 20-meter pit. Every day the snail climbs 5 meters up but at night it slides down 4 meters. How many days does it take before the snail reaches the top?
Answer: The snail reaches the top of the pit on the 16th day. On the first day, the snail reaches a height of 5 meters and slides down 4 meters at night, and thus ends at a height of 1 meter. And, on the second day, he reaches 6 meters but slides back to 2 meters. On the third day, he reaches 7 meters but slides back to 3 meters. And, on the fifteenth day, he reaches 19 meters but slides back to 15 meters. On the sixteenth day, he reaches 20 meters, so now he is at the top of the pit.
8. Continue the sequence: 2, 4, 8, 16, 32…
Answer: It’s 64 because you double each consecutive number.
9. How can you get 23 using only the number 2?
Answer: 22+2:2=23.
10. 81 x 9 = 801. What do you need to do to make this equation true?
Answer: Turn it upside down. 108 = 6 x 18.
Number Riddles with Answers
Number riddles with answers can be a godsend for children who struggle with math. For example, how can you subtract two from 5 and leave 4? If you take the letters F and E out of the word FIVE, you get IV.
1. I am an odd number. Take away a letter and I become even. What number am I?
Answer: Seven.
2. I add six to eleven, and get five. Why is this correct?
Answer: When it is 11 a.m., adding six hours makes it 5 p.m.
3. In a new hotel containing 100 rooms, Tom was hired to paint the numbers from 1-100 on the doors. How many times will Tom have to paint the number 8?
Answer: 20. Many people have been guessing anywhere from 9 to 19, but the correct answer is 20.
4. What number can you subtract half from to obtain a result of zero?
Answer: The number 8. It’s made up of two zeros, one on top of the other.
5. What is the smallest number that increases by 12 when it is flipped and turned upside down?
Answer: The answer is 86. When it is turned upside down and flipped, it becomes 98, which is 12 more than 86.
6. Robert and David played several golf matches against each other in a week. They played for a pizza at each match, but no pizzas were purchased until the end of the week. If Robert and David had the same number of wins at any time, those pizzas were canceled. Robert won four matches (but no pizzas), and David won three pizzas. How many rounds of golf were played?
Answer: 11. David won seven matches — four to cancel out Robert’s four wins and three more to win the pizzas.
7. It is the reciprocal of 9 multiplied by 2, and the product of 9 times 9. What is the number?
Answer: 81.
8. There are eight balls with eight different numbers in them: 1, 3, 5, 7, 9, 11, 13, 15. Select three balls that equal 30.
Answer: Flip the nine and turn it into a 6 and then the three balls are 6, 11, and 13.
9. One is to three as three is to five and five is to four and four is the magic number.
What is the pattern here?
Answer: Four. The word One has 3 letters, in the word three there are 5 letters, in the word five there are four letters and four has four letters in it as well. Whatever number you’ll go back to four, and that’s why it’s the magic number
10. How did the soccer fan know before the game that the score would be 0-0?
Answer: The score is always 0-0 before the game.
Number Riddles for Adults
Have your parents ever boasted about being the top student? Try asking number riddles for adults. For example, I was 21 the day before yesterday and will be 24 next year. What day is my birthday? Today is January 1st, not December 31st.
1. At the time of shipping, Jacob can place 10 small boxes or 8 large boxes into a carton. A total of 96 boxes were sent in one shipment. The number of small boxes was less than large boxes. What is the total number of cartons he shipped?
Answer: 11 cartons. 4 small boxes (410 = 40 boxes) 7 large boxes (78 = 56 boxes). So, Jacob shipped 96 boxes and 11 total cartons
2. What single digit appears most frequently between and including the numbers 1 and 1,000?
Answer: The most common digit is 1! Did you figure out why? Every number 1-9 appears exactly the same number of times in every ten numbers. But because we included the number 1,000, there’s an extra occurrence of the number 1. In total, the number 1 appears 301 times, and every other number appears 300 times.
3. I am a 3 digit number between 400 and 800. My digits add up to 15. My ten’s digit is twice my hundreds digit. What number am I?
Answer: 483.
4. Mrs. Jones was very proud of her apple tree. One autumn, after harvesting her apples, she called her three sons together. “Here are 150 apples,” she said. “I want you to take them to the market tomorrow and sell them for me.” She gave Paul 15 apples, Nick 50, and Ben 85. “Your job,” added Mrs. Jones, “is to sell the apples in such a way that each of you brings home the same amount of money.” How do they do it?
Answer: The first buyer purchases 12 dozen apples at $1 per dozen. Paul sells him one dozen and has three apples left; Nick sells him four-dozen and has two apples left; Ben sells him seven-dozen and has one apple left. Then a second buyer comes along and buys all their remaining apples for $3 apiece. The three brothers head home with $10 each.
5. How much is this bag of potatoes?” asked the man. “Thirty-two pounds divided by half of its own weight,” said the grocer. How much did the potatoes weigh?
Answer: 8 lbs.
6. Bella has two books, one book is faced upside-down, and the other book is placed in a way that the top of the book is facing Bella. What is the total sum of the first pages of both the books?
Answer: 1+1=2. The first page of every book is marked as one, doesn’t matter how they are placed.
7. I will be everything if you put me on my side. I will be nothing if you cut me in half. What am I?
Answer: The number 8. If you put 8 on its side, it will become an infinity symbol ∞. If you cut it on its “waist,” it will become two zeros 0 0.
8. I am a three digit number. My tens digit is five more than my ones digit. My hundreds digit is eight less than my tens digit. What number am I?
Answer: Number 194.
9. I am not a multiple of 10. My tens digit is a multiple of 3. If you round me to the nearest 100, I become 500. Who am I? A) 460 B)535 C) 530 D)592
Answer: 535.
Number Riddles for Kids
Number riddles for kids to help them learn more. E.g., how many eggs can you fit in a 2m x 2m empty basket? There is only one! After that, the box is no longer unoccupied.
1. What do the numbers 11 and 88 have in common?
Answer: They both look the same upside-down and backward.
2. How many 7’s are between 0 100?
Answer: 20. 7, 17, 27, 37, 47, 57 ,67, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 87, 97.
3. What can you put between a 7 and an 8 so that the result is greater than a seven, but less than an eight?
Answer: A decimal. 7.8 is greater than 7, but less than 8.
4. A little girl goes to the store and buys one dozen eggs. As she is going home, all but three eggs break. How many eggs are left unbroken?
Answer: Three.
5. How many months of the year have 28 days?
Answer: All of them, because every month has at least 28 days.
6. What two whole, positive numbers have the same answer when multiplied together as when one is divided by the other?
Answer: Any number and 1.
7. One brother says of his younger brother: “Two years ago, I was three times as old as my brother was. In three years’ time, I will be twice as old as my brother.” How old are they each now?
Answer: The elder is 17, the younger 7. Two years ago, they were 15 and 5 respectively, and in three years’ time, they will be 20 and 10.
8. This is a number which is more than 4 and less than 8. And 1 more than the fingers you have in your one hand. Can you help me find the number?
Answer: 5.
9. What is half of 2 plus 2?
Answer: Half of 2 equals 1; 1 +2 = 3.
10. It is endless and boundless, looks like a sleeping 8 number. What is it?
Answer: Infinity ∞.
Number Riddles and Jokes
Number jokes and riddles are entertaining until you have to take a real math test or quiz at school. When the instructor brings you the exam paper, you start to feel a little nervous.
1. There is a man with his horse going to town. The man went to the town on Monday. He stayed there for 3 days and then he came back on Friday. How? His horse was not tired, the man wasn’t sleepy.
Answer: The horse’s name was Friday.
2. Five without four is iron, how?
Answer: Take middle two characters, its the roman number 4 (IV). Five without four is Fe. Fe is the iron chemical element name.
3. A man has 9 children. Half of them are boys. How is this possible?
Answer: They are all boys.
4. If four men can build four tables in four hours, how many can eight men build in eight hours?
Answer: 16 tables.
5. Two ducks lay 3 eggs in 3 minutes. Consider this as the maximum possible speed; how many ducks will be needed to get 300 eggs in 300 minutes?
Answer: 2 ducks.
6. If it takes 5 men 9 hours to build a bridge, how long would it take 10 men to build the same bridge?
Answer: Zero, the bridge is already made.
7. There are 6 black socks, 8 brown socks, 4 blue socks, and 2 red socks in my wardrobe. How many socks should be pulled out in order to get a matching pair for sure?
Answer: 5.
8. An odd man was to do eight jobs, why did he only do 4?
Answer: He only did jobs 1, 3, 5, and 7.
9. Do you know the special trick to turn seven into an even number?
Answer: Remove the s!
10. If you go to the movies and you’re paying, is it cheaper to take one friend to the movies twice or two friends to the movies at the same time?
Answer: It’s cheaper to take two friends at the same time. In this case, you would only be buying three tickets, whereas if you take the same friend twice, you are purchasing four tickets.
11. Why is 69 so scared of 70?
Answer: Because once they fought, and 71.
Final Thoughts on Number Riddles
Number riddles are underappreciated because they are used to test the intelligence of others. If the other person is unable to reach the correct answer, you begin to mock them.
Instead, have you considered using math riddles in a way that will benefit you? You can use them to improve your math skills. Who knows, you might end up with the highest grade in your class.
We’ve all met someone who despises math. It could be genuine advice to them to solve as many number riddles as possible.
That brings our collection of number riddles with answers to a close. We hope our selection was both challenging and enjoyable.
Share them with your friends, family, colleagues, and homeroom understudies. Even if some are difficult, even the oldest and least-experienced numeric riddle solver will improve their ability to solve confusions.
Remember the famous saying, “careful discipline yields promising results.” Have fun, and keep the puzzles coming!
