Math isn’t just about formulas and equations—it’s also about problem-solving, logic, and thinking outside the box. Whether you’re a student looking to sharpen your mind, a teacher searching for warm-up activities, or just someone who loves a good puzzle, these math brain teasers are sure to get your gears turning.
Try them out, share them with friends, or use them in your classroom. Scroll down for the answers (but no peeking until you’ve given them a real shot!).
1. The Missing Dollar
Three friends check into a hotel room that costs $30. They each contribute $10. Later, the hotel clerk realizes the room only cost $25, so he sends the bellboy to return $5. The bellboy decides to keep $2 and gives $1 back to each friend.
Now each friend has paid $9, totaling $27. Plus the $2 the bellboy kept makes $29.
Where is the missing dollar?
2. The Farmer’s Dilemma
A farmer has 17 sheep and all but 9 run away.
How many sheep does the farmer have left?
3. The Age Puzzle
I am twice as old as I was 10 years ago, and half as old as I will be in 20 years.
How old am I?
4. The Math Test
On a math test, you score 70 on the first half and 90 on the second half.
What is your final score?
5. The Consecutive Numbers
The sum of five consecutive numbers is 100.
What are the numbers?
6. The Clock
What is the angle between the hour and the minute hands of a clock at 3:15?
7. The Number Reversal
I am a two-digit number. My tens digit is four more than my ones digit. If you reverse my digits, the new number is 27 less than the original.
What number am I?
8. The Candy Jar
You have 10 bags of candy, each containing 100 pieces. One bag has candies that each weigh 1.1 ounces; the rest contain candies that each weigh 1 ounce.
Using a digital scale once, how can you determine which bag has the heavier candies?
9. The Race
You pass the person in second place in a race.
What place are you in now?
10. The Birthday Riddle
Two people are born on the same day, same month, same year, and have the same parents—yet they are not twins.
How is this possible?
✏️ Think You’ve Solved Them All? Here Are the Answers:
- There is no missing dollar. The $27 includes the $25 for the room and the $2 the bellboy kept. You can’t add the $2 again.
- 9 sheep—“All but 9” ran away.
- 40 years old—Let x be your age. Then: x = 2(x – 10), so x = 40.
- 80—Assuming both halves are weighted equally: (70 + 90)/2 = 80.
- 18, 19, 20, 21, 22—Their sum is 100.
- 7.5 degrees—At 3:15, the hour hand is 7.5 degrees past 3. Minute hand at 90 degrees. Difference = 82.5 degrees.
- 62—Tens digit is 6, ones digit is 2. 26 is 27 less than 62.
- Weigh 1 candy from bag 1, 2 from bag 2, …, 10 from bag 10. Total weight should be 55 ounces. Every 0.1 ounce over means the heavier bag is that number.
- Second place—You took their spot.
- They are triplets (or quadruplets, etc.)—Not just twins!
Ready for More?
Math brain teasers are a great way to stretch your brain and have fun with numbers. Want more puzzles like this delivered to your inbox or printable versions for your classroom? Leave a comment below and let me know!
