# Questions tagged [formation-of-numbers]

For puzzles about forming numbers using other numbers and mathematical operations.

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### Use the digits 1, 9, 9, 8 to get 81 [closed]

Using the digits $1, 9, 9$ and $8$ in that order, and the operations $+$, $-$ and/or $\times$ in any order between pairs of digits, create an expression that equals $81$.  Normal precedence rules ...
238 views

### Make all the ones

Given all the digits $0,\dots,9$ and using each digit exactly once, What is the smallest possible number you can make whose digits are all $1$'s? The only operations that are allowed are: ...
184 views

### 1984 - take the digits 1,9, 8 and 4 and make 369

Part II... Next year is the 70th anniversary of the publication of the book 1984 by George Orwell. Here is a puzzle to start the anniversary celebrations off a bit early ... Warm up Can you ...
188 views

### 1984 - take the digits 1,9, 8 and 4 and make 246

Next year is the 70th anniversary of the publication of the book 1984 by George Orwell. Here is a puzzle to start the anniversary celebrations off a bit early ... Warm up Can you assemble a formula ...
136 views

### A Math Puzzle with a Pattern

Inspired from a puzzle marathon, here is a math puzzle. There is a pattern with this set of numbers (not in the creation though). According to the pattern, what is the logical replacement for the ...
296 views

### Form the biggest squaring number

You are going to start from any number with distinct digits lower than four digits (such as $a$, $ab$, $abc$) and you will apply the rule below: Take the square any number you want in the number (you ...
754 views

### make this sum using only +

A bit of a speed question this, first correct answer gets the check. Although you are allowed to use computers, it might be quicker not to. By placing only $+$ signs between some of the numbers on the ...
11k views

4k views

### Make 4 4 4 4 = 30,31

Follow up question to Make 5 5 5 5 = 19 Can you find a way to make: $4\ 4 \ 4 \ 4 = 30$ and $4\ 4 \ 4 \ 4 = 31$ by adding any operations or symbols on the left side of the equations? You can ...
2k views

### Maximize the number of factorials in your solution to 6 5 4 3 = 1

Using the same rules as Make 6 5 4 3 = 1, but maximize the number of factorials. You may not take the factorial of 1 or 2. This is harder than it looks. A great answer has six factorials, an ...
10k views

### Make 6 5 4 3 = 81

Can you find a way to make: 6 5 4 3 = 81 by concatenation and/or adding any of (and only) these mathematical operators: + - × ! ÷ ^ standard parentheses () You cannot add other numbers to the ...
1k views

### Make 6 5 4 3 = 1

Can you find a way to make: 6 5 4 3 = 1 by concatenation and/or adding any of (and only) these mathematical operators: + - × ! ÷ ^ standard parentheses () You cannot add other numbers to the ...
14k views

### Make 5 5 5 5 = 19 [closed]

Can you find a way to make: $5\ 5 \ 5 \ 5 = 19$ by adding any operations or symbols? You can use only these symbols: $+,\ -,\ *,\ !,\ /,\ \hat\, ,\ ()$. It is limited to this list, and ...
151 views

### Making 49 from 5, 1, 3, 4 [closed]

I have these numbers: 5, 1, 3, 4. There are four different ways to make 49 - what are they?
64 views

### Find the operators

Assume you are using a basic calculator and press these numbers in order. Replace each question mark with plus, minus, multiply and divide may be used, but no sign should be used more than once. In ...
89 views

### The Yerata number system

There are only a few words for numbers in the Yerata1 language. Here are all of them, in random order: imu tere nuopo rowintom rowintom rowintom imu tere nuopo re nuopo rowintom re nuopo nuobo imu ...
17k views

### Combine 3, 3, 5 & 7 to get 24

Using operators plus, minus, multiplied by and divide by, and as many brackets as you want, can you do a formula which uses 3, 3, 5 and 7 to make 24? Each number must be used and can only be used ...
1k views

### A mazegic square

So you like mathematical diversions? Here's something new for you then ...
518 views

### Use 2,3,4,5 to get 26 using only + - * /

Use 2,3,4,5 and + - * / only once each (it's not necessary to use all of them) to equal 26. I know 2 answers, but there is a 3rd (or more) :)
279 views

### A challenging Magic Square

Find a 3x3 Magic Square where each row, column and both diagonals result in positive number 9 You are allowed any of the 4 math operations : add, subtract, multiply or divide. NO OTHER OPERATIONS ...
261 views

### When is my date of birth?

___4,_4,_4 This is my real date of birth, because it looks unique, I try to do a simple operation, and I get a number 222. In fact it is able to solved without looking at the hint, but I'm trying to ...
234 views

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### Make 439204 from Φ (Golden Ratio)

In my last formation-of-numbers question I somehow tricked myself, because I wanted to make a puzzle about a number that looks like a year. But the complicated solution I thought of turned out to be ...
3k views

### Make 2008 from Φ (Golden Ratio)

I know that questions of the form "Use [arbitrary set of numbers] to make 2018" seem to be not very well recieved in the last days. That's why this puzzle is about making 2008. But instead of using ...
274 views

### Integers around a circle with consecutive pairs differ to a square

Inspired by this puzzle : Integers around a circle with consecutive pairs adding to a square The integers 1 to 50 are placed around a circle in such a way that the difference of any two of them which ...
1k views

### Use four 8's to make the number 2016

Previous question: Use two 2's, two 1's, and two 8's to make the number 2018 Background: I was trying to add some new elements (hopefully creative and interesting) to this traditional type of number-...
4k views

### Use two 2's, two 1's and two 8's to make the number 2018

This is another number formation question. You must use each of $2$, $1$ and $8$ exactly twice to make the number $2018$. The rules are Allowed symbols: $+$, $-$, $\times$, $\div$, $($, $)$, \$\sqrt{\...
204 views

### Find the combination algorithm for 16 digit numbers [closed]

Find the combination algorithm for numbers that will be generated. And the numbers are: 0535 8549 9933 3564 0500 7197 6709 9534 0531 3170 7802 8731 The numbers ...
19k views

### 10 9 8 7 6 5 4 3 2 1 = 2018

Add the four basic operators × ÷ + −: 10 9 8 7 6 5 4 3 2 1 to get the total 2018. Keep the order; do not combine numbers. Don't use any brackets. Use all four operators at least once.