Questions tagged [formation-of-numbers]
For puzzles about forming numbers using other numbers and mathematical operations. Use with [mathematics]. Puzzles using this tag should carefully specify the allowed operations.
26 questions from the last 365 days
-6
votes
7
answers
202
views
How do you get 5 by using the numbers 2, 2, 3 and 5?
You can use addition, multiplication, subtraction, and division as many times as you want but can only use the numbers one time each.
-6
votes
1
answer
97
views
make 2026 using all the digits from 0 to 9 and any or all of the following operators: +, -, *, /, powers, roots, factorial
Make a mathematical sum that has an answer of 2026 using all the digits from 0 to 9 and any or all of the following operators: +, -, *, /, powers, roots, factorial
10
votes
3
answers
737
views
9/16/25 operations challenge
Use the numbers 9, 16, and 25 in that order to create numbers 1-10. You can use addition, subtraction, multiplication, division, parenthesis, and the square root as many times as you want
- 111
-4
votes
2
answers
245
views
Make numbers 1-40 using only 2, 0, 2, 6
Try to make all numbers 1-40 using the digits 2, 0, 2, 6.
Rules:
Use all four digits exactly once.
Allowed operations: +,−,×,÷,! (factorial), $x^y$ (exponentiation), √ (square root).
Parentheses and ...
3
votes
3
answers
220
views
With given numbers, make the number 87 [closed]
Try to make the number 87 using 5,5,1,0
Rules:
Use all four digits exactly once.
All mathematical operations are allowed.
Concatenations are not allowed.
- 31
8
votes
1
answer
386
views
What is a Short Integer™?
No, a Short Integer™ is not a Short Integer!
If an integer conforms to a special rule, I call it a Short Integer™.
Each integer can be tested. This is not a definitive list of Short Integers™.
Short ...
- 7,968
8
votes
2
answers
974
views
Make 987654321 = 123456789 by adding as few as operators as possible
This equation is false. Make it true by adding as few operators as possible:
987654321 = 123456789
Only the operators + - ...
user106806
-5
votes
3
answers
295
views
1 22 333 4444 55555 666666 7777777 88888888 999999999
You are given the following 8 numbers:
22
333
4444
55555
666666
7777777
88888888
999999999
Answer the three following sub-puzzles, allowed operators are: $+,-,\div,\times$ and parenthesis.
Obtain 1 ...
- 7,968
2
votes
5
answers
452
views
Can you get 100 using only 9,1,6,6 each once? [closed]
I was playing Math Flux and the winning goal was 100. We had combined digits out so we can combine 2 digits together
Can you get 100 using the digits 9,1,6,6 using only each digit once?
- 39
11
votes
1
answer
790
views
Make 101520 with 6 6's
Make the number 101520 with 6 6's.
Rules:
All 6's must be used exactly once
The operations allowed are addition (+), subtraction (-), multiplication ($\times$), division ($\div$), exponents and ...
- 4,590
-2
votes
1
answer
188
views
What equation equals 20 but only the numbers 1 2 0 3 can be used and they can be only used once and no other numbers can be used [closed]
I have tried grouping the numbers but that doesn’t work
6
votes
12
answers
3k
views
Seven nines to make ninety
Use seven 9s to make 90.
The allowed operations:
$+, -, \times, \div, x^y, \sqrt{\square}$, parentheses
$\sqrt[\square]{x}$ is not allowed. (e.g. $\sqrt[9]{9^{9
}}=9$ isn’t allowed.)
Have fun!
- 5,192
1
vote
4
answers
213
views
From 1 – 6 and 7 – 10 make 37
1 _ 2 _ 3 _ 4 _ 5 _ 6 = 7 _ 8 _ 9 _ 10 = 37
Programming Operations are allowed. (+, -, ×, ÷, ^, parentheses)
I made this simple puzzle.
- 5,192
13
votes
2
answers
656
views
Make 2025 using 3 single digits
Make 2025 using exactly 3 single digits (not necessarily different).
Rules:
Allowed operations: $+,−,\times,\div,!$ (factorial)
Parenthesis are allowed and can be interpreted as binomial coefficient.
...
- 13.2k
8
votes
8
answers
2k
views
Make 987 using 1, 3, 5, 7, 9
Make the number 987 using digits 1, 3, 5, 7, 9.
Rules:
Use all five digits exactly once.
Allowed operations: $+,−,\times,\div,!$ (factorial), $x^y$ (exponentiation),$\sqrt{x}$ (square root).
...
- 689