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.
479 questions
-6 votes
7 answers
190 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
92 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
243 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
219 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
384 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
-1 votes
1 answer
283 views
I count fractions of rotation and have two digits, what AM I?
I count fractions of rotation and have two digits, what AM I? I use letters over digits. I don't use a pair of digits for my most significant digit from one of my series. I can use any one of my ...
-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!
- 5,182
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.
- 5,182
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