Questions tagged [formation-of-numbers]

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

Filter by
Sorted by
Tagged with
18
votes
4answers
1k views

A mazegic square

So you like mathematical diversions? Here's something new for you then ...
5
votes
3answers
780 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) :)
4
votes
1answer
302 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 ...
3
votes
2answers
273 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 ...
0
votes
2answers
234 views

Factor the number 23 into four numbers $a + b \sqrt{2} + c \sqrt{3} + d \sqrt{6}$ [closed]

We know that $23$ is a prime number nonetheless, I'm asking to find 4 numbers $a,b,c,d > 0$ such that $23$ factors. $$ 23 = A \times B \times C \times D \text{ with } A,B,C,D = a + b \sqrt{2} + c \...
2
votes
10answers
16k views

Make numbers 1-30 using 2, 0, 1, 9

This is very similar to the 2, 0, 1, 8 problem. Just try to make all numbers 1-30 using the digits 2, 0, 1, 9. Rules: Use all four digits exactly once Allowed operations: +, -, x, ÷, ! (factorial), ...
8
votes
4answers
4k views

Get 59 from 1,9,4,8 in order [closed]

I’m stuck on trying get $59$ by the numbers $1,9,4,8$ in order. I have no idea if it’s possible, I made it for 1-70 just not 59. I made it without order: $(-1+8)*9-4$ You can use not only the basic ...
-2
votes
2answers
274 views

Making 30 using 3 3s [closed]

Hope that all can answer the question. It's an IQ! How can one make 30 using 3 only three times?
-6
votes
4answers
334 views

find out the missing expressions [closed]

10 10 10 10 = 1 10 10 10 10 = 2 10 10 10 10 = 3 10 10 10 10 = 4 10 10 10 10 = 5 10 10 10 10 = 6 10 10 10 10 = 7 10 10 10 10 = 8 10 10 10 10 = 9 10 10 10 10 = 10 You can only add ...
15
votes
2answers
615 views

Ode to convergence

Taking a numeral core (digits: a non-quad four) digits I ordered, then lesser I minused, till evolve I couldn't more. What is this unfathomably clunky poem all about?
3
votes
3answers
280 views

Puzzling Number Boxes

Found this puzzle as a translation question. The Chinese is fairly simple, it just asks to solve for the ? in the bottom right square. The actual puzzle though, I have no clue about. Can any of you ...
-4
votes
1answer
503 views

What is the smallest counting number you can create higher than 1? [closed]

What is the smallest integer you can create using 1,2,3,4,5,6,7,8,9 that is strictly greater than 1? You can use any mathematics symbol. You must use all nine numbers. You can't use the same number ...
4
votes
2answers
281 views

Numbers and Countries

The relations given below. According to these values, solve the last relationship. Germany - Kenya = 7 Mexico - Brazil = 9 Turkey - Australia = 18 Norway - Ghana = 7 Korea - ...
7
votes
2answers
1k views

Pick seven numbers so that every operation gives same result

Pick seven numbers so that every operation (addition, subtraction, multiplication, but not division) gives the same result. For subtraction, you may take the result's absolute value. Numbers cannot ...
5
votes
3answers
2k views

Mathematics IQ puzzle, solving puzzle by looking at neighboring digits [closed]

Can anyone solve this puzzle? I have tried many times but I could not find any symmetry or sequence. \begin{array} {|c|c|c|} \hline 3&25&5\\ \hline 16&9&6\\ \hline 125&36&18\\ ...
8
votes
1answer
877 views

IBM Research Puzzle – 5-ops implementation of erasure code

I found this interesting puzzle on IBM Research Puzzling Page called Ponder This; specifically, here. Design a storage system that encodes 24 information bits on 8 disks of 4 bits each, such that: ...
1
vote
1answer
162 views

What is the relation between these numbers?

Based on the relation between the numbers of each shape, find the number for the question mark. 337 339 549 569 Source: Iraninan Ph.D University Enterance 2017
2
votes
9answers
2k views

How to use the numbers 3, 5, 6, and 7 to get 100? [closed]

Any mathematics symbols and processes to use the numbers 3, 5, 6, and 7 once each to get 100.
5
votes
1answer
424 views

What is the minimum number of digits required to make the numbers 1-20?

What is the minimum number of digits required to make the numbers $1-20$? Any $n$ consecutive numbers can be counted as a $n$-digit consecutive number. So, $$12\\34$$ has the numbers $$1, 2, 3, 4, ...
5
votes
2answers
475 views

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 ...
13
votes
5answers
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 ...
7
votes
3answers
279 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 ...
8
votes
4answers
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-...
12
votes
5answers
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{\...
3
votes
0answers
216 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 ...
0
votes
4answers
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.
-6
votes
2answers
3k views

Make numbers 33-100 using only digits 2,0,1,8

Use the numbers 2, 0, 1, and 8 (ALL of them...only ONE time each) to make every integer from 33 to 100. Allowed operations: +, -, x, ÷, ! (factorial), exponentiation, square root and Parentheses No ...
5
votes
8answers
4k views

How to use 2,0,1,8 to make 51? [closed]

How to use the number 2,0,1,8 to make 51? You can use any operation except for multiple factorials and you can concatenate numbers, ex.2,0=>20 You can take the square root of a number without a ...
6
votes
4answers
5k views

Can you make 2 0 = 1 5? [closed]

Can you find a way to make 2 0 = 1 5 by adding any operations or symbols? You can use symbols such as these: +, -, *, !, ^, (). It is not limited to this list.The symbols may be added either between ...
43
votes
10answers
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 ...
8
votes
2answers
7k views

Is Ron a mathematical prodigy?

I and Ron were talking casually over coffee. Just then a thought sprung into my mind; could there exist numbers such that if their digits are reversed, for example $123\to321$, the new number is ...
-5
votes
3answers
188 views

Get 20160 with 5 2's and any Mathematical Operator [closed]

Here is a mathematical riddle: Find a way to get 20160 with 5 2's and any mathematical operators you want. Have fun! Don't forget that I said any. Feel free to look online for crazy whacky math ...
3
votes
2answers
2k views

Make numbers 93 using the digits 2, 0, 1, 8

I have a 1 to 100 building challenge with 2, 0, 1, 8, all made but 93 is not made. I need your help! This is similar to the "Four fours" puzzle, but using the digits 2, 0, 1 and 8. Rules: Use all ...
24
votes
6answers
78k views

Make numbers 1 - 30 using the digits 2, 0, 1, 8

It's 2018 so let's repeat last year's challenge with new digits. This is similar to the "Four fours" puzzle, but using the digits 2, 0, 1 and 8. Rules: Use all four digits exactly once Allowed ...
3
votes
1answer
150 views

From the information given below- prove that Z = 4561

If- ONE * THREE * FIVE = 225 NINE * SEVEN + TWELVE = X 225 + X = Y 10,18,32,56,93,146,? ? + Y = Z Prove that, Z = 4561
-2
votes
1answer
196 views

What is the next number in the integer sequence?

What is the next number in the following sequence? 25 27 30 34 39 45 52 60 69 79 69 60 52 45 39 34 30 26 22 18 82 78 74 70 66 67 64 60 65 80 ?
7
votes
1answer
486 views

Two Christmas trees

To each Christmas tree : Put two $+$, two $-$, and two $×$, to the yellow triangles. in a row, there must be different operators (so between $[2,0,1,7]$ all $3$ operators must appear) $A - B$ means $|...
4
votes
1answer
192 views

Numbers in the wheel

Arrange the numbers 3 to 27 onto the wheel using these rules: The modulus of two adjacent numbers must equal with the number between them. Modulus here means the remainder when the bigger number is ...
4
votes
4answers
628 views

Complete numbers on Clock

I have a different kind of clock at my home. Image of Clock: 5 o'clock on this clock means 1 o'clock actually. Display of data in table: Can you complete all the numbers on this clock by finding ...
-6
votes
2answers
125 views

Expressing numbers as sum of two squares and two powers of 2

It has been shown that the smallest integer, greater than 1, that cannot be represented as a sum of two squares and at most two powers of 2 is 535,903. Show how to express 535,902 as the sum of two ...
-2
votes
1answer
376 views

Make numbers 1-31 with 1,9,7,8

I am stuck with some of the solutions. These are rules: Use all four digits exactly once Allowed operations: +, -, x, ÷, ! (factorial), exponentiation, square root, squaring, parentheses Thank you ...
3
votes
1answer
145 views

Another loop of integers with consecutive terms adding to a square

The integers 1 to 50 are placed around a circle in such a way that the sum of any two of them which are adjacent is a perfect square. Of these integers, all but the prime integers were removed. ...
1
vote
4answers
460 views

Finding pattern of numbers

I have this puzzle for adding 2 numbers (Or sequences) Does anyone have an idea about how this addition works? $$ 5+1=9\\3+1=10\\5+2=21\\8+2=23\\9+0=28\\4+3=?? $$
31
votes
1answer
783 views

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 sum of any two of them which are adjacent is a perfect square. Of these integers, the even numbers are then removed. Restore them....
7
votes
6answers
2k views

How can you get 125 from 2,3,4,5,6?

You are allowed to use the four standard operations (+-/*) to get 125, using each of the following digits exactly once: 2, 3, 4, 5, and 6. I came up with an answer, but took me a while; curious to ...
4
votes
2answers
324 views

Find the ? in this grid

Find question mark in this grid with numbers. csv version: 9,6,7,3 2,4,7,6 4,1,5,8 3,0,3,? Hint: You use all numbers to find ? and it is much more simple ...
1
vote
3answers
2k views

Make 38, 44, 46 using 2,3,8,7?

Using BODMAS/BIDMAS* and the numbers and signs 2,3,7,8, (), -,+,÷,× can you make 38, 44, 46. You can only use each number once. I can't figure it out myself Brackets Order Division Multiply Add ...
4
votes
1answer
163 views

Draw out a Battle!

I'm thinking of a number. It's 5 digits long There's a 5 between a 7 and a 2. The second-biggest number is on the far right. The average digit value is equal to the second-lowest digit. The smallest ...
2
votes
2answers
838 views

Mathematical riddle [duplicate]

Part one: You are presented with ten incomplete equations: 0 0 0 = 6 1 1 1 = 6 2 2 2 = 6 3 3 3 = 6 4 4 4 = 6 5 5 5 = 6 6 6 6 = 6 7 7 7 = 6 8 8 8 = 6 9 9 9 = 6 Your job is to fill in mathematical ...
15
votes
2answers
2k views

My colleague gave me a number puzzle

My colleague probably has left work now, he is no longer responding. He gave me this puzzle and asked me to fill in the '?': ...

1 2 3 4 5 7