Welcome to the ultimate brain workout! Math riddles are a fantastic way to sharpen your mind, enhance problem-solving skills, and have fun all at once. Whether you’re a math whiz or just love a good challenge, these 100 math riddles will put your skills to the test. Each riddle comes with an answer, but try not to peek until you’ve given it your best shot. Ready? Let’s dive in!
100 Math Riddles
1. Riddle: I am an odd number. Take away one letter, and I become even. What number am I?
Answer: Seven.
2. Riddle: If you multiply this number by any other number, the answer will always be the same. What number is it?
Answer: Zero.
3. 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?
Answer: 194.
4. Riddle: What comes once in a minute, twice in a moment, but never in a thousand years?
Answer: The letter ‘M’.
5. Riddle: How many sides does a circle have?
Answer: Two (the inside and the outside).
6. Riddle: What number do you get when you multiply all of the numbers on a telephone’s number pad?
Answer: Zero (since the product includes 0).
7. Riddle: The ages of a father and son add up to 66. The father’s age is the son’s age reversed. How old could they be? (3 possible answers)
Answer: 51 and 15, 42 and 24, 60 and 06.
8. Riddle: What has a head, a tail, but does not have a body?
Answer: A coin.
9. Riddle: If you add 1.5 to a number and then double the result, you get 12. What is the number?
Answer: 5.25.
10. Riddle: I have keys but no locks. I have space but no room. You can enter but not go outside. What am I?
Answer: A keyboard.
11. Riddle: If you divide 30 by half and add ten, what do you get?
Answer: 70.
12. Riddle: A bat and a ball cost $1.10. The bat costs $1.00 more than the ball. How much does the ball cost?
Answer: 5 cents.
13. Riddle: How many times can you subtract 5 from 25?
Answer: Once, because after you subtract, it’s not 25 anymore.
14. Riddle: If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
Answer: 5 minutes.
15. Riddle: What 3 positive numbers give the same answer when multiplied and added together?
Answer: 1, 2, and 3.
16. Riddle: If there are three apples and you take away two, how many do you have?
Answer: Two.
17. Riddle: How can you make seven even?
Answer: Remove the ‘S’ (Seven becomes Even).
18. Riddle: I am a number, and when you take away half of me, nothing remains. What number am I?
Answer: 0.
19. Riddle: A man is pushing his car along a road when he comes to a hotel. He shouts, “I’m bankrupt!” Why?
Answer: He’s playing Monopoly.
20. Riddle: What can you put between a 7 and an 8 to get a result greater than 7 but less than 8?
Answer: A decimal point (7.8).
21. Riddle: If 2 is company and 3 is a crowd, what are 4 and 5?
Answer: 9.
22. Riddle: I am a five-letter word, and I am a fruit. Take away my first letter and I am a crime. What am I?
Answer: Grape (Grape – G = Rape).
23. Riddle: There is a basket containing 5 apples. How do you divide them among 5 children so that each child has an apple and one apple stays in the basket?
Answer: Give 4 children each an apple and give the fifth child the basket with the apple in it.
24. Riddle: If you write down all the numbers from 1 to 100, how many times would you write 8?
Answer: 20 times.
25. Riddle: Which is heavier: a ton of feathers or a ton of bricks?
Answer: Neither, they both weigh a ton.
26. Riddle: If a rooster lays an egg on top of a barn roof, which way will it roll?
Answer: Roosters don’t lay eggs.
27. Riddle: What 4-digit number multiplied by 4 gives the same number but with the digits reversed?
Answer: 2178 (2178 × 4 = 8712).
28. Riddle: Two fathers and two sons are in a car, yet there are only three people in the car. How?
Answer: They are grandfather, father, and son.
29. Riddle: I am a number that is one less than a multiple of 10, and also one more than a multiple of 9. What number am I?
Answer: 9.
30. Riddle: How can you add eight 8’s to get the number 1000?
Answer: 888 + 88 + 8 + 8 + 8 = 1000.
31. Riddle: What is the smallest positive number that is evenly divisible by all the numbers from 1 to 10?
Answer: 2520.
32. Riddle: A cube has how many edges?
Answer: 12.
33. Riddle: If it took 8 men 10 hours to build a wall, how long would it take 4 men to build it?
Answer: None, the wall is already built.
34. Riddle: What number do you get if you subtract 57 from 93?
Answer: 36.
35. Riddle: If you have a bee in your hand, what do you have in your eye?
Answer: Beauty (because “beauty is in the eye of the beholder”).
36. Riddle: What is the square root of 16?
Answer: 4.
37. Riddle: How many prime numbers are there between 1 and 10?
Answer: Four (2, 3, 5, 7).
38. Riddle: What has numbers on it but can’t be used for counting?
Answer: A clock.
39. Riddle: If you multiply this number by itself, you get the same number. What is it?
Answer: 1.
40. Riddle: How many sides does a hexagon have?
Answer: Six.
41. Riddle: How can you arrange four nines to make 100?
Answer: 99 + (9/9) = 100.
42. Riddle: What is 25% of 200?
Answer: 50.
43. Riddle: If a train is moving at 60 miles per hour, how long will it take to travel 180 miles?
Answer: 3 hours.
44. Riddle: If two’s company and three’s a crowd, what are four and five?
Answer: 9.
45. Riddle: What is the result when you multiply 8 by 7?
Answer: 56.
46. Riddle: If you were to spell out numbers, how far would you have to go until you would find the letter “A”?
Answer: One thousand.
47. Riddle: How many times can you subtract 10 from 100?
Answer: Once, after that it’s 90.
48. Riddle: How many months have 28 days?
Answer: All of them.
49. Riddle: What number is three times the sum of its digits?
Answer: 27.
50. Riddle: Which weighs more, a pound of feathers or a pound of bricks?
Answer: Neither, they both weigh a pound.
Read also: 100 Hard Riddles for Adults and Kids With Answers
51. Riddle: If a plane crashes on the border of the United States and Canada, where do they bury the survivors?
Answer: Survivors aren’t buried.
52. Riddle: A barrel of water weighs 20 pounds. What must you add to it to make it weigh 12 pounds?
Answer: A hole.
53. Riddle: If there are 12 fish and half of them drown, how many are left?
Answer: 12, because fish don’t drown.
54. Riddle: How many times does the digit 5 appear between 1 and 100?
Answer: 20 times.
55. Riddle: What occurs twice in a week, once in a year, but never in a day?
Answer: The letter ‘E’.
56. Riddle: What 2-digit number is the same when you read it upside down?
Answer: 69.
57. Riddle: What is the only number that, when spelled out in English, has its letters in alphabetical order?
Answer: Forty.
58. Riddle: I am a number that is one less than a multiple of 10, and also one more than a multiple of 9. What number am I?
Answer: 9.
59. Riddle: What two whole, positive numbers have the same answer when multiplied and added together?
Answer: 2 and 2.
60. Riddle: What 5-digit number becomes half when divided by 2 and gives the same number when divided by itself?
Answer: 12321.
61. Riddle: What is the next number in the sequence: 1, 11, 21, 1211, 111221?
Answer: 312211.
62. Riddle: What is the sum of the angles in a triangle?
Answer: 180 degrees.
63. Riddle: I add six to eleven and get five. Why is this correct?
Answer: When you add 6 hours to 11 o’clock, you get 5 o’clock.
64. Riddle: What has a bottom at the top?
Answer: Your legs.
65. Riddle: How many seconds are there in a year?
Answer: 12 (January 2nd, February 2nd, etc.).
66. Riddle: What number do you get if you divide 60 by 1/2 and add 10?
Answer: 130.
67. Riddle: I am an odd number; take away an alphabet, and I become even. What number am I?
Answer: Seven.
68. Riddle: What comes once in a minute, twice in a moment, but never in a thousand years?
Answer: The letter ‘M’.
69. Riddle: What is always in front of you but can’t be seen?
Answer: The future.
70. Riddle: How can you make the number one disappear by adding to it?
Answer: Add a ‘G’ and it’s gone.
71. Riddle: What number is less than 100 and has exactly 9 factors?
Answer: 36 (1, 2, 3, 4, 6, 9, 12, 18, 36).
72. Riddle: What number is twice the sum of its digits?
Answer: 18.
73. Riddle: What 3-digit number is equal to the sum of the cubes of its digits?
Answer: 153 (1^3 + 5^3 + 3^3 = 153).
74. Riddle: What is the next number in the sequence: 2, 3, 5, 9, 17?
Answer: 33 (each number is one less than double the previous number).
75. Riddle: If 1 = 3, 2 = 3, 3 = 5, 4 = 4, 5 = 4, then what is 6?
Answer: 3 (it represents the number of letters in the word of the number).
76. Riddle: What is a four-digit number in which the first digit is one third the second, the third is the sum of the first two, and the last is three times the second?
Answer: 1349.
77. Riddle: What is the difference between a cat and a comma?
Answer: A cat has claws at the end of paws, and a comma is a pause at the end of a clause.
78. Riddle: How many months have 28 days
Answer: All of them
79. Riddle: What is the smallest positive number that is evenly divisible by all the numbers from 1 to 10?
Answer: 2520.
80. Riddle: What is the value of Pi to four decimal places?
Answer: 3.1416.
81. Riddle: What mathematical symbol can be placed between 5 and 9, to get a number greater than 5 and smaller than 9?
Answer: A decimal point (5.9).
82. Riddle: What 3-digit number is the sum of the cubes of its digits?
Answer: 370 (3^3 + 7^3 + 0^3 = 370).
83. Riddle: What number is one less than twice its reciprocal?
Answer: 2.
84. Riddle: How many squares are there on a standard chessboard?
Answer: 204 (there are 64 1×1, 49 2×2, 36 3×3, 25 4×4, 16 5×5, 9 6×6, 4 7×7, and 1 8×8).
85. Riddle: What 3-digit number consists of three distinct digits such that the sum of the digits is equal to the product of the digits?
Answer: 123.
86. Riddle: What is the sum of the first 50 even numbers?
Answer: 2550.
87. Riddle: What is the result when you multiply 6 by 9?
Answer: 54.
88. Riddle: If 7 is equal to 13, 9 is equal to 17, and 13 is equal to 25, what is 15 equal to?
Answer: 29.
89. Riddle: What two-digit number is the square of the sum of its digits?
Answer: 81 (9^2 = 81).
90. Riddle: What is the next number in the sequence: 2, 6, 12, 20, 30?
Answer: 42 (each number is n^2 + n, where n = 1, 2, 3, 4, 5).
91. Riddle: What four-digit number multiplied by 4 gives the same number but with the digits reversed?
Answer: 2178 (2178 × 4 = 8712).
92. Riddle: What is the only even prime number?
Answer: 2.
93. Riddle: What is the smallest positive integer that is a perfect square and a perfect cube?
Answer: 64.
94. Riddle: What is the sum of all the angles of a hexagon?
Answer: 720 degrees.
95. Riddle: What is the next number in the sequence: 1, 4, 9, 16, 25?
Answer: 36 (squares of 1, 2, 3, 4, 5, 6).
96. Riddle: What two-digit number is both a square and a cube?
Answer: 64 (4^3 and 8^2).
97. Riddle: What number is 25% more than 80?
Answer: 100.
98. Riddle: What is the sum of all the prime numbers between 1 and 10?
Answer: 17 (2 + 3 + 5 + 7).
99. Riddle: What is the next number in the sequence: 2, 3, 5, 7, 11?
Answer: 13 (prime numbers).
100. Riddle: How many sides does a nonagon have?
Answer: Nine.
Read also: 101 Funny Riddles to Tickle Your Funny Bone
Hope you enjoyed these brain teasers! Did you manage to solve them all without peeking? Share these riddles with friends and see who truly is the smartest among you!
Conclusion
Congratulations on making it through all 100 math riddles! Whether you cracked them all or had to check a few answers, I hope you found the challenge stimulating and enjoyable. Math riddles are a great way to keep your mind sharp, improve problem-solving skills, and see numbers from a fresh perspective. If you enjoyed these riddles, share them with friends and family to see who can solve the most. Remember, it’s not just about getting the correct answer but enjoying the process of figuring it out. Keep puzzling and stay curious!