You might want to break out a calculator, because it takes a genius to solve these tricky math riddles
đź’¦ FULL SET: List/math riddles - HD Photos!
It’s math o’clock!
Whether you take math classes regularly or it’s been a minute since you last quadraticled an equation, math riddles are for everyone. From math for adults (like calculating the tip at a restaurant and dividing the check among six friends) to solving Sudoku puzzles, math is a part of all our lives. But don’t worry: You don’t have to be a math whiz to challenge yourself with these puzzles. We’ve ranked them from easy to hard, so you can warm up with some simpler math riddles and end with the real head-scratchers. After all that number crunching, you’ll be ready for even more challenging riddles. There’s nothing like that “A-ha!” feeling when you crack a difficult riddle (or even an easier one), so keep reading and we’ll get started.
Get Reader’s Digest’s Read Up newsletter for more fun facts, humor, travel and tech all week long.
1
/
7
đź’¦ FULL SET: List/math riddles - HD Photos!
Using only addition, add eight 8s to get the number 1,000
Answer: 888 + 88 + 8 + 8 + 8 = 1,000. This is the kind of math riddle you can work out with times tables, or by simple logic. First, get as close to 1,000 as you can (888). From there, it’s easy to figure out the rest.
2
/
7
I add six to eleven, and get five. Why is this correct?
Answer: Tricksy, tricksy! You have to think more broadly. Here’s a hint: Think about the numbers on a clock. When it is 11 a.m., adding six hours makes it 5 p.m.
3
/
7
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 from 1 to 9 appears exactly the same number of times in every 10 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.
4
/
7
You know 2 + 2 comes to the same as 2 x 2. Now find a set of three different whole numbers whose sum is equal to their total when multiplied.
Answer: The three different whole numbers whose sum is equal to their total when multiplied are 1, 2 and 3.
5
/
7
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 the answer (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 tens 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.
6
/
7
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.
7
/
7
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 in this tricky egg riddle by four-fold (i.e., 1.5 x 4 = 6), the number of eggs increases 16 times: 16 x 1.5 = 24.
Why trust us
Reader’s Digest is known for our humor and brain games, including quizzes, puzzles, riddles, word games, trivia, math, pattern and logic puzzles, guessing games, crosswords, rebus, hidden objects and spot-the-difference challenges. We’ve earned prestigious ASME awards for our entertainment content and have produced dozens of brainteaser books, including Word Searches, Word Power, Use Your Words, Fun Puzzles and Brain Ticklers, Mind Stretchers, Ultimate Christmas Puzzles and more. Our 10 published volumes of Mind Stretchers were edited by Allen D. Bragdon, founder of The Brainwaves Center and editor of Games magazine. Read more about our team, our contributors and our editorial policies.
