50 Math Riddles With Answers (Easy, Medium & Hard)

Love numbers and brain teasers? These math riddles with answers are perfect for kids, students, teachers, and adults who enjoy a good puzzle. We split them into easy, medium, and hard levels, and every answer comes with a short explanation so you actually learn the trick.

🟢 Easy Math Riddles With Answers

Warm up your brain with these simple number puzzles. Great for kids and beginners.

Here are 18 riddles to try:

1. I am an odd number. Take away one letter and I become even. What am I? Seven — Take away the letter S and SEVEN becomes EVEN.
2. What is 3 + 3 × 3? 12 — Multiply first: 3 + 9 = 12.
3. If you have 3 apples and you take away 2, how many do you have? 2 — You took 2, so you have 2.
4. What goes up but never comes down? Your age — Age only increases.
5. How many months of the year have 28 days? All 12 — Every month has at least 28 days.
6. What is half of 2 + 2? 3 — Half of 2 is 1, plus 2 equals 3.
7. Which weighs more: a kilo of feathers or a kilo of stones? Neither — A kilo is a kilo.
8. What comes once in a minute, twice in a moment, but never in a thousand years? The letter M — Count the letter M in each word.
9. If you multiply me by any other number, the answer stays the same. What am I? Zero — Anything times zero is zero.
10. What number is spelled with its letters in alphabetical order? Forty — F-O-R-T-Y is in alphabetical order.
11. Forward I am heavy, backward I am not. What am I? Ton — TON spelled backward is NOT.
12. What 3 positive numbers give the same answer when added together and multiplied together? 1, 2 and 3 — 1 + 2 + 3 = 6 and 1 × 2 × 3 = 6.
13. If there are 6 apples and you take 4, how many do you have? 4 — You took 4 apples, so you have 4.
14. What is the next number in this sequence: 2, 4, 8, 16, ? 32 — Each number doubles.
15. How many times can you subtract 10 from 100? Once — After that you are subtracting from 90, then 80.
16. What has 13 hearts but no organs? A deck of cards — Hearts is one of the four suits, with 13 cards.
17. What is 7 + 7 ÷ 7 + 7 × 7 − 7? 50 — Divide and multiply first: 7 + 1 + 49 − 7 = 50.
18. If a rooster lays an egg on top of a roof, which way does it roll? It doesn’t — Roosters don’t lay eggs.

🟡 Medium Math Riddles With Answers

A step up: these need a little more thinking, but no advanced math.

Here are 17 riddles to try:

1. 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? 5 cents — If the ball is 5¢, the bat is $1.05, totaling $1.10.
2. If 5 machines make 5 widgets in 5 minutes, how long would 100 machines take to make 100 widgets? 5 minutes — Each machine still makes one widget in 5 minutes.
3. What is half of two-thirds of three-quarters of 100? 25 — Three-quarters of 100 is 75, two-thirds of 75 is 50, half of 50 is 25.
4. I am a 3-digit number. My tens digit is 5 more than my ones digit, and my hundreds digit is 8 less than my tens digit. What am I? 194 — Ones = 4, tens = 9, hundreds = 1.
5. How many times does the digit 9 appear between 1 and 100? 20 — Ten times in the ones place, ten times in the tens place (90–99).
6. What is the smallest 3-digit number divisible by 7? 105 — 98 is only 2 digits, so the next multiple is 105.
7. A farmer has 17 sheep. All but 9 die. How many sheep are left? 9 — ‘All but 9’ means 9 survive.
8. Using the digits 1, 2, 3, 4, 5 exactly once, what is the largest even number you can make? 54,312 — Put the biggest digits first and end with the largest even digit, 2.
9. If it takes 6 men 6 days to dig 6 holes, how long does it take 1 man to dig half a hole? Trick question — You can’t dig half a hole — a hole is a hole, whatever its size.
10. What number gives a remainder of 1 when divided by 2, 3, 4, 5, or 6, but no remainder when divided by 7? 301 — Check numbers of the form 60k + 1; 301 is the first divisible by 7.
11. Two numbers add up to 20 and multiply to 96. What are they? 12 and 8 — 12 + 8 = 20 and 12 × 8 = 96.
12. How many squares are on a standard chessboard? 204 — 64 small squares plus all the larger squares they form.
13. What is 111,111,111 × 111,111,111? 12,345,678,987,654,321 — The digits climb to 9 and back down again.
14. If 3 cats catch 3 mice in 3 minutes, how many cats does it take to catch 100 mice in 100 minutes? 3 cats — Each cat catches one mouse every 3 minutes, so 100 minutes is plenty of time.
15. What comes next: 1, 11, 21, 1211, 111221, ? 312211 — Read each term aloud: ‘three 1s, two 2s, one 1’ and so on.
16. A clock takes 5 seconds to strike 6 o’clock. How long does it take to strike 12 o’clock? 11 seconds — There are 5 gaps between 6 strikes (1 second each), so 11 gaps at 12 o’clock.
17. What is the sum of all whole numbers from 1 to 100? 5,050 — Pair them up: 1+100, 2+99 … fifty pairs of 101.

🔴 Hard Math Riddles With Answers

The real challenge. Take your time — and check the explanation if you get stuck.

Here are 15 riddles to try:

1. I am a 2-digit number. My digits add up to 12, and reversing my digits increases me by 18. What am I? 57 — 5 + 7 = 12, and 75 − 57 = 18.
2. A father is 3 times as old as his son. In 15 years, he will be only twice as old. How old are they now? Son 15, father 45 — 3x + 15 = 2(x + 15) gives x = 15.
3. What is zero factorial (0!)? 1 — By definition, 0! equals 1.
4. What is the 10th number in the Fibonacci sequence? 55 — 1, 1, 2, 3, 5, 8, 13, 21, 34, 55.
5. A snail climbs 3 feet up a 10-foot well each day and slips back 2 feet each night. On which day does it get out? Day 8 — It reaches 7 feet after 7 days, then climbs 3 feet on day 8 to reach the top.
6. What is the angle between the clock hands at 3:15? 7.5 degrees — The hour hand has moved a quarter of the way past 3 while the minute hand points at 3.
7. What number squared, plus 24 squared, equals 25 squared? 7 — 7² + 24² = 49 + 576 = 625 = 25².
8. How many trailing zeros does 25! (25 factorial) have? 6 — Factors of 5 appear at 5, 10, 15, 20, and twice at 25.
9. What is the only even prime number? 2 — Every other even number is divisible by 2.
10. What is the sum of the first 10 prime numbers? 129 — 2+3+5+7+11+13+17+19+23+29 = 129.
11. Think of a number. Double it, add 6, divide by 2, then subtract your original number. What is left? 3 — The algebra always works out: (2n + 6)/2 − n = 3.
12. What is 15% of 200, plus 10% of 150? 45 — 30 + 15 = 45.
13. How many edges does a cube have? 12 — Four around the top, four around the bottom, four vertical.
14. If you flip a fair coin 3 times, what are the odds of getting heads all 3 times? 1 in 8 — ½ × ½ × ½ = 1/8.
15. A shop gives a 20% discount, then takes another 10% off the reduced price. What is the total discount? 28% — $100 → $80 → $72, so 28% off overall.

❓ Math Riddles FAQ

What is a math riddle?
A math riddle is a puzzle that uses numbers, logic, or arithmetic tricks. The answer is often simpler — or sneakier — than it first looks.

Are these math riddles good for kids?
Yes! The easy section is written for kids ages 7 and up, and teachers use riddles like these as fun classroom warm-ups.

What is the hardest math riddle here?
Try the clock-angle and factorial riddles in the hard section — most adults need a minute for those.

Want more puzzles? Try our easy riddles, hard riddles, or the full 500 riddles collection.