# Questions tagged [calculation-puzzle]

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

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0answers
53 views

### General aptitude question [duplicate]

Thomas bought a train set with 25 toy engines that run at different speeds. The train set has five parallel tracks that can be built to race the engines. After each round, Thomas notes down the ...
1answer
899 views

### My grandfather's coins

When my grandfather died, he left his fine collection of coins, not more than 2500 of them, to his children, a different number to each of them, and in decreasing amounts according to their ages. To ...
3answers
2k views

### What is the age of the old man?

In autumn of the year 2003 an old man was asked about his age. He answered: "I was born on a Sunday morning in summer and I celebrated my seventh birthday on a Sunday morning too!" How old ...
0answers
73 views

### Make numbers 1-100 using the digits 2, 0, 2, 2 [closed]

Rules: Must use all numbers 2, 0, 2, 2 combined to form an equation that equals 1-100 The order of 2, 0, 2, 2 can be reversed Except for 2, 0, 2, 2, no other numbers can be used You can use 2, 0, 2, ...
1answer
118 views

### Work to time ratio! [closed]

Once Valera left the house, walked to the villa, painted 11 fence boards there, and returned home 2 hours after leaving. Another day, Valera went to the villa with Olga, together they painted 8 fence ...
5answers
1k views

### Split 1 through 6 into a product of 24 and sum of 12

How many ways are there to split the numbers 1, 2, 3, 4, 5, and 6 into two groups, such that the product of the numbers in one group is 24 and the sum of the numbers in the other group is 12? An ...
3answers
878 views

### Calculation Sudoku

Here is a new quiz from my daily quiz calendar. I'm trying to find a way to solve it. The numbers 1-6 should be filled in. And like a sudoku, each row and each column should contain each number ...
1answer
82 views

### Not a music rebus

What is the 6-letter word that associates with this rebus? Helpness Meter 1: Helpness Meter 2:
1answer
81 views

### Find the pattern of the following series: 7 × 3 = 5? [closed]

I recently came across a certain question which I was not able to solve. It was as follows: 7 × 3 = 5 9 × 5 = 41 15 × 11 = ?? Can you tell me the logic behind this?
1answer
262 views

### Multiplying English numbers is strange too

It seems that the English-speaking people multiply the numbers in the very same way that the Portuguese add them: while the latter say that 2+2=8, the former claim that 2×2 is 8: ...
2answers
198 views

### Pirates dividing booty around a circular table

A group of pirates have plundered one of his majesty's cargo ships and they all carried as much gold coins as each one could find. When they get back to their ship, they sit at a round table and pass ...
1answer
115 views

### A Clear, Simple, Geometry Problem [closed]

Draw a shape consisting of all the points equidistant from a specific point. Furthermore, draw a segment passing through a side of the shape exactly twice, and draw another segment so that it also ...
3answers
594 views

### Calculation - the hard way

This is a puzzle I love to play with my math students and I hope you will enjoy it too: You are given the numbers 1, 2, 3, 4, and 5 exactly once. Your target is a number, e.g. 36. Can you create a ...
1answer
87 views

### Reverse Engineer Chess Software Calculations

TLDR Just the Puzzle Given a number n and a weight w the function f will result in a weighted number r as follows. f(n, w) = r n can be a number from 0 to 200 w can be a number from -100 to 100 (...
6answers
2k views

### Does this equation make sense?

"The two sides of this equation appear to be different, don't they?" asked Grandpa I looked at the numbers he had written on a piece of paper and nodded in agreement. 2011 = 1012 "Can ...
7answers
996 views

### To equip hand sanitizers

There was an event held by a group. In this COVID-19 era, there were many hardships in equipping quarantine supplies, in addition to carrying out the event. Several bottles of the same hand sanitizer ...
1answer
342 views

### A Cryptic Cryptarithm

An entry in Fortnightly Topic Challenge #48: Unusual tag mix Solve these puzzles to reveal why I made them. Matriarch mostly prepared oats for American airline location? (8) AIRLINE + LOCATION = ? 51 ...
3answers
175 views

### In computer science Using the digit 4 exactly four times and 4 signs only and only the operation + is allowed how to get 10? [closed]

in computer science Using the digit 4 exactly four times and 4 signs only and only the operation + is allowed how to get 10? for example: $(44 - 4) / 4 = 10$ does not work because 44 is a number ...
3answers
570 views

### Table of mathematical expressions - fill in 1-9

Fill in the numbers 1 through 9 in the 9 empty cells (each number appears exactly once) to make the row and column expressions equal to the number at the end of the row or column. Regular math ...
2answers
83 views

### A challenge to make 1 - 100 [closed]

So this challenge is you have (don't have to) make the numbers 1 - 100 by using the numbers 1, 3, 4, 6 only once. I'm stuck on how to make 54. Can anyone help me? P. S. You can use +, -, ÷, x, ! And ...
2answers
103 views

### digits in descending order equals 2022

Happy New Year! Here's a nice puzzle for you guys. 2021 has started and can be written as $$(-9+8)*7-6*(5-(4+3)^{2+1})+0=2021$$ Ofcourse many other solutions are possible! So, the obvious puzzle is:...
1answer
147 views

### Cut the string!

There are five pieces of blue string on the table with different lengths, the total length of which is 30 cm. There are also five pieces of red string with different lengths, the total length of which ...
2answers
237 views

### Place 4 players to make 6 distances between pairs

Is it possible to place 4 players on a football field in such a way that the 6 distances between every pair of them are 1, 2, 3, 4, 5, 6 meters? Source: Moscow Math Olympiad 2001 (Look Inside to Page ...
2answers
87 views

### Drawing a line with a ruler [closed]

Imagine we have a ruler on which just numbers 0 and 2 and 5 are marked and the rest numbers are erased. How could we draw a 6 cm line by this ruler?
1answer
146 views

### Four rational numbers whose product is 10 and whose sum is 0

It has been shown that every positive integer is the product of four rational numbers whose sum is 0. Thus: ...
1answer
311 views

### Long division cryptarithm - KLMN/HIJ = K

The problem statement: Solve the following long division problem. Each letter represents a unique digit (0-9) ...
3answers
97 views

### Form a magic square with assorted numbers

Arrange the following numbers in a way such that all rows, columns and the diagonals add up to the same number. ...
1answer
114 views

### Use only πs to get e

I am taking this puzzle from inspiration from the Four Fours to get Pi puzzle. The puzzle rules are just slightly different. Here are the rules: You are trying to get as close to e as possible with ...
4answers
237 views

### Addition table with hidden digits

Similar to the previous puzzle, find the values behind the letters. ...
2answers
243 views

### Yet another mixed sum

An instance of this puzzle is here: https://www.theguardian.com/science/2020/nov/16/can-you-solve-it-the-srcmalbed-nmebur-plzuze a) It has been swhon taht to raed a txet the oedrr in wihch the ...
1answer
100 views

### How do you find the sum of the digits contiguous to one which is situated in a three by three table?

The problem is as follows: I am placing the numbers from 1 to 9 in the squares of a 3 x 3 board. I start by placing the numbers 1, 2, 3 and 4 as shown in the figure. For the number 5, the sum of the ...
1answer
362 views

### Some mathematical magic

The magician will perform some mathematical magic. He asks his guest to secretly pick any two digit number and then perform a number of operations on it. If the number is even, divide by 2, if it is ...
1answer
266 views

### This puzzle's value is 334

The 28th of october is valued by 40. This sentence is valued by 17. This paragraph is valued by 143. This puzzle is valued by 334. Can you give the value of Puzzling StackExchange?
1answer
621 views

### Chain Puzzle: Tabletop Games #05 - It's Yahtzee, Jim, but not as we know it

This is the fifth Chain Puzzle in the Tabletop Games series, in which all puzzles are themed around board games, card games, tile games, and the like. The answer to this puzzle is a thematic word or ...
3answers
110 views

### Find the mass of a specific weight given information about other groups

The problem is as follows: Vincent has 19 different calibrated weights whose weights are 1g, 2g, 3g, and so on up to 19g. Nine of them are made from steel, nine are made from brass, and the remaining ...
4answers
153 views

### Given pairs of weights find individual values

The problem is as follows: A kid has five marbles. These marbles have different weights and the child weighs them in pairs in all possible ways. He records the weights in his notebook. These are the ...
2answers
186 views

### Find the competition rankings of three people based on their final scores

I found this puzzle in my Logic and Reason book from 2000's. The topic is ordering information. From the looks of it seems to be an adaptation from a reprinted version of Martin Gardner's 70's book of ...
2answers
1k views

### A logical puzzle about a pet shop

I am an undergraduate student studying languages and give private lessons to secondary school students to help them learn English. Recently one of them suddenly asked me during a lesson whether I ...
2answers
103 views

### Sum with letters, find the values

In the following addition setup, each letter correspond to a unique digit. Find the different values of the letters. Requirement: r is not equal to 0. ...
2answers
148 views

### Using the number 8 6 4 2 = either 19 or 17 [closed]

The numbers can only be used once. You can use any operator from BEDMAS.
2answers
117 views

### Using the numbers 8642 = 9 [closed]

Using any calculation in BEDMAS use the numbers 8645 = 9 Numbers can only be repeated once.
2answers
438 views

### The art of computer programming

EDIT: I know we are not supposed to edit in new requirements after first posting but as far as I understand it this requirement is implicit in all questions here: Explain your answer! At least a ...
0answers
109 views

### XOR -Is it possible to prove that if A=C⊕B then B=C⊕A and C=A⊕B using Boolean algebra only? [closed]

If you write out the truth tables then it's pretty simple but I was wondering if there was a nicer proof using Boolean algebra only
1answer
512 views

### 10 dummies play a game of Among Us

This puzzle is based on Among Us; however, knowledge of the game is not required for this puzzle. 10 dummies are on a spaceship, in which there are 3 impostors and 7 crewmates. For the sake of ...
4answers
2k views

### 77-digit number divisible by 7 with seven 7s

The smallest number divisible by 7 with seven 7s is trivially 7777777. Then, what is the greatest 77-digit number divisible by 7 which contains seven 7s?
2answers
342 views

### Find the missing value in the given figure

Find the missing value value in the given below figure Choose the correct option : (a) 22 (b) 34 (c) 36 Could anyone give me hint to crack the logic in this figure to get the missing value? I tried a ...
7answers
1k views

### Math Challenge: Create 8

Using only $2$, $7$, and $7$ (each one must be used only once) and only using the operations $+$, $-$, $\times$, $\div$, $\textrm{^}$, and parentheses, make 8. You can also use decimals.
1answer
161 views

### How to get these outputs using these inputs?

Examples of inputs and outputs: Input: 3 7 20 Output: 1 Input: 17 2 1651 Output: 34 Input: 4 3 5 Output: 2 Input: 1000000000 1000000000 1000000007 Output: 49 Input: 27 37 100 Output: 99
1answer
167 views

### My Latest Password

-What is your password?- my niece asks me. -It is a four digit number. -I know that. -It is divisible by precisely three primes. -Tell me more. -It has at least one common divisor greater than 1 with ...
2answers
166 views

### How many steps for matchstick-Lychrel numbers?

The Lychrel number is famous in the recreational mathematics. The process about the Lychrel numbers reverses arrangement of the previous number. Mimicking Lychrel numbers, I would like to devise ...