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# Questions tagged [formation-of-numbers]

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

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13k views

### Making π from 1 2 3 4 5 6 7 8 9

There have been two other questions here and here that are similar to this one, but this changes the rules up a little. Your job is to approximate $\pi$ using the sequence of digits (in order): 1 2 ...
20k views

### Make 0 0 0 0 = 8

Can you find a way to make: $0\ 0 \ 0 \ 0 = 8$ by adding any operations or symbols? You can use only these symbols: $+,\ -,\ *,\ !,\ /,\ \hat\, ,\ ()$. It is limited to this list, and ...
147k views

### 1 2 3 4 5 6 7 8 9 = 100

The sequence of numbers $1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 9$ has the property that you can insert mathematical operators in between the numbers from $1$ to $9$ and make the expression evaluate to 100. For ...
30k views

### Can you make 1 1 1 1 = 5? [closed]

Can you find a way to make 1 1 1 1 = 5 by adding any operations or symbols? You can use symbols such as these: +, -, *, !, ^, (). It is not limited to this list. Good Luck! P.S. You can not add any ...
5k views

### What is the smallest set of letters that can spell any integer? [closed]

Today my 9-year-old nephew told me that he can spell any integer in English using only 9 letters. This is how he's doing it: ...
6k views

### Making 103 from 4 zeroes

As the title suggests, the puzzle here is making the number 103 by using exactly four 0s and the following operations: $+$ Addition $-$ Subtraction $\times$ Multiplication $\div$ Division $\sqrt{a}$ ...
7k views

### Rendering the number 10,958 with the string 1 2 3 4 5 6 7 8 9

Brazilian mathematician Inder Taneja has found a way of expressing every number between 1 and 11,111, except 10,958, by inserting mathematical operators in between the numbers 1 2 3 4 5 6 7 8 9 and ...
3k views

1k views

### Does this mathy square have any solutions? (And how many?)

Consider a $5\times5$ grid of math operators and numbers that encodes 8 math equations: A + B = C = + + + + D + E = F + = = = = G = H + I There are 3 horizontal ...
1k views