# Questions tagged [calculation-puzzle]

A puzzle that involves numerical calculations, such as multiplication and addition. Use with the [mathematics] tag.

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### Making a multiplying magic square

To allow new users to solve this puzzle and earn reputation points, I encourage all users whose reputation is 200 or more to not post an answer until 48 hours after this question is posted. Thank you! ...
• 12.1k
1 vote
209 views

### Solve the Alphametic: SOUNDS / WOW = ELK

This is a long-division problem in which letters are substituted for numbers. Solve the problem. Determine the number value of each letter; and when the letters in each one have been arranged in order ...
1k views

### Making 1353 using Four fours

As the title says, the goal for this puzzle is making 1353 out of simply 4, 4, 4 and 4. Concatenation is not allowed. Here are all of the allowed operators. Addition (+), Subtraction and negatives (-)...
152 views

### Use 1 6 7 8 (all numbers) to equal 2 [closed]

Create an equation using 1, 6, 7 and 8 to equal 2. Can use brackets, plus, minus, subtract, multiply.
152 views

### The 50 game between two players, selecting numbers between 1 and 10 inclusive + variations

This is a cross-post from MSE: https://math.stackexchange.com/questions/4900281/the-50-game-between-two-players-selecting-numbers-between-1-and-10-inclusive Let's play a game with two players, with ...
• 143
207 views

### Connect the dots x Crosswords

About the puzzle: This puzzle is a crossover of "connect the dots" puzzles and crossword puzzles. It requires the solver to place dots on the graph using crossword-like clues. Then, dots ...
• 1,153
235 views

### Ernie and the Kzijekistanian Coup

A couple of days ago I noticed an article in the International News section of our local newspaper headlined Kzijekistanian Empress Abdicates. Reading on, I discovered that she "… stepped down ...
• 14k
2k views

### Where is the large cook promotion?

The time is 8:59 or ... Where is the large cook promotion? 3,4,2 Partial answers are welcome. A complete answer will use/explain all of the above.
• 12.1k
1k views

### Fix the addition so that the sum is 1,111

111 333 555 777 + 999 ----- 1,111 The above addition is not correct. Can you fix it? For which numbers $n$ can you change $n$ of the $15$ digits of the ...
• 12.1k
286 views

### April Fools Origami Update

Me (Sunny Lu) and Ωmega_3301 have made a special April Fools edition of origami puzzles. The objective is to fold a shape into a rectangle with uniform thickness. The thickness will be given to you. ...
• 3,185
2k views

### Fewest number of prisoners needed

You are an assistant to the king, who has scheduled a party tomorrow. There are 1000 wine bottles in the king's possession, and unfortunately, 3 of them are poisonous. Consuming from any of these ...
1k views

### BROWN + YELLOW = PURPLE [closed]

This is a Cryptoarithmatic, where each letter denotes a single digit number. Find values of all the letters. BROWN + YELLOW = PURPLE Please show your method for solving this question.
• 69
428 views

### How to make 2012 by using 2, 0, 1, 2?

How to make $2012$ by using $2, 0, 1, 2$? Allowed Operations: Addition, Subtraction, Multiplication, Division, $!$ (factorial), subfactorial ( $!n$), primorial (product of the first $n$ primes), ...
1k views

### Walking in a random direction

I walk $\pi$ km in one direction followed by $\pi$ km in another direction. In expectation how far am I now from my starting location? Both directions are chosen uniformly at random between $0^{\circ}$...
• 36.2k
66 views

### Water and Milk Mixture Problem [closed]

There is a 100 liters of milk in a container. 5 liters of milk removed and replaced with water Once again 5 liters of mixture removed and replaced with water Now how you calculate to find out the ...
• 11
160 views

### Unique day of the year

I made this challenge. Astronomers announced that the sky and the moon will appear violet-velvet next week, and one of their workmates is also celebrating her birthday on the day that the moon will ...
5k views

### Make 27 using 1, 1, 1, 1

Make the number 27 using 4 instances of the digit 1. You must use all 4 digits to make it count. Here are the allowed operators: Addition (+), subtraction (-), multiplication (*), division (/) Square ...
498 views

### Make expressions equal to 6 using exactly four 4s

You must use all four 4s. You may use addition (+). You may use subtraction (-). You may use multiplication, such as with asterisks (*) and/or grouping symbols. You may not use any division. You ...
• 1,788
1k views

### When was the power restored?

The power went out last night. The stove clock is flickering and showing 7:54 AM. The cell phone shows 7:07 AM. When was the power restored?
• 205
1 vote
107 views

### Happy New Year 2024 free drinks party [closed]

You have many friends and they like to drink*. So you decided to throw a whole-day party and invite them for a party with a free drink every hour. During the first hour one friend comes and you offer ...
• 30.6k
281 views

On this quiz, 005227 encodes the name Abby and 716123863 to Taylor. The key has something to do with encoding each letter as base 3 (c=010) and then writing the numbers in a column and reading down. ...
4k views

### A strange operator on my new calculator

Yesterday, I bought a new calculator in an antique shop. I wanted to try some basic operations to see if it was working well. Everything felt right, except for the + sign: it seemed like it was ...
• 3,790
1k views

### can you figure out how five plus nine equals six? [closed]

Quick riddle here for you 5 + 9 = 6... how? I look forward to hearing your answers, and I am writing this part in the hope it allows me to submit. (it did!)
• 55
981 views

### Relatively prime numbers

Can you fill in the circles with numbers such that: Each pair of circles connected by one line contains relatively prime numbers Each pair of circles connected by two lines do not contain relatively ...
210 views

### Find the wrong number in the given series

I found this question in an Indian Highschool Reasoning Olympiad. I tried looking for any relation using powers of 2 but failed.
173 views

### Kind of a Number Pattern

I found this problem in a highschool Reasoning olympiad in India.
813 views

### Minimum number of turns

You have 64 identical-looking boxes numbered from 1 to 64, each weighing a distinct amount. On a turn, you can tell your friend two numbers between 1 and 64, and she will tell you which of the ...
• 336
152 views

### A Squared Cipher

While looking for squares, I stumbled across these numbers, which seemed to form a message: ...
• 753
413 views

### A 4x4 sudoku shouldn't be that hard, right? Right?

Note: this is not in conjunction with my Minesweeper puzzles Got this idea from one of Cracking the Cryptic's videos, I don't remember which one though. This exact puzzle is still overall unique. ...
• 2,413
4k views

### Let's make a huge number with only tiny numbers

Using only three 1s and two 2s (i.e. 1,1,1,2,2), can you generate the number 55? You can use all mathematical operators you know, such as floor function, factorial, powers/indices*, etc., but ...
509 views

### Shiny cryptarithm

Here's a little puzzle I made today: $$\sqrt{\text{ILLUMINATE}^{\mathstrut}} = \text{LIGHT}$$ Most usual rules of alphametic puzzles apply here: the same letter always represents the same digit, and ...
• 1,170
886 views

### Before the Common Era

This is part 39 of the puzzle series Around the World in Many Days. Each part is solvable on its own. Dear Puzzling, The grid on the left-hand side is a KenKen puzzle. Fill the grid so that every row ...
• 77.8k
289 views

### Python Conundrum 2: Guess The Place

Python Conundrum: The Series The key: The puzzle: ...
• 1,153
1k views

### Sums in a (very small) box

This puzzle is part of the Monthly Topic Challenge #14: Think inside the (very small) box!. Place the digits 1 to 9 in the box below in such a way that in each row, each column and each diagonal, one ...
• 30.6k
227 views

### Figure Out The Language: Min

Imagine there is a programming language in which you can only evaluate expressions. Expressions have operators and constants. There are three types of constants. Numbers - Any number from 0 to ...
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353 views

### Find the ciphering method 4

Link to the entire series. The message: ...
• 1,153
399 views

### Find the ciphering method 2

Link to the entire series. The message: 3, 53, 48751, 9247757, 294914580539 The answer is a 13 letter word: UNDERSTANDING Hint 1:
• 1,153
293 views

### Find the ciphering method using deciphered message

Link to the entire series. Ciphered message: ...
• 1,153
238 views

### Decipher a long sequence of numbers

51699624576811268526783109824167925197245652924177251787241782538786302873119768312852668312686625268245686752824473216878253830287925175273039778250852831287672527245665263006725397251762529312811498 ...
• 1,153
74 views

### Find the largest number with unique digits, that is divisible by each of its digits [duplicate]

Find the largest number with unique digits, that is divisible by each of its digits. For example 132 has unique digits and is divisible by 1, 2 and 3. But it is not the largest such number. Can you ...
540 views

### Help a woman from ancient Rome find out how her husband is doing

Let's go back 2000 years. A woman named Valeria received a strange message from her husband Claudius who is a frumentarius. The message: ...
• 1,153
617 views

### Operator! Some Product!

Happy Venndredi all, A relatively straightforward one! The three overlapping ellipses form seven curved regions and there are seven tiles. Your task is to place exactly one tile per region so that ...
• 3,674
6k views

### Combine 1,3,3,7 to get 10

I tried lots of combinations but could not find a solution. Each number has to be used exactly once, the allowed mathematical operators are Addition: + Subtraction: - Negation: (unary prefix) - ...
• 259
3k views

### What does this mathematical operator do?

The solution to this puzzle is one I came up with when working on this puzzle: What is the answer of this math puzzle? For two natural numbers a,b, can you figure ...
• 612
1k views

### What is the answer of this math puzzle?

One of my friend brought this simple-looking math puzzle to me, but it was harder than it seems. I tried several ideas including simple arithmetic operations, and even considering base-n. ...
• 71
343 views

### Nuts and screws

Imagine that you are given a box with n nuts and n screws. Each screw have different size (diameter) and on each screw there is ...
• 263
365 views

### A and B don't know their own values

() isn't used mathematically in this puzzle. () means that whatever is inside should be evaluated in the most suitable and ...
761 views

### Is Sumplete always analytically solvable?

I am stuck here at Sumplete. I have tried looking for numbers that must be used/must not be used using https://combinationsumcalculator.com/ and all of them are either not used in all combinations (...
• 121
2k views

### Three clocks problem

Three clocks which show the times for three different time zones are hanging on a wall. The length of their minute hands is the same - but not the lengths of their hour hands. The lengths of the hour ...
• 1,699