Category Archives: recreational math

9×54 Ramanujan sudoku

This is a variation of the popular puzzle Sudoku.

Ramanujan Sudoku 9x54
Ramanujan Sudoku 9×54

The word “RAMANUJAN” occupied 89 cells and numbers 1 to 9 are used 9 times each and the balance filled with 1 to 8. 8 along with the properties of NORMAL SUDOKU.

1) The entire word “RAMANUJAN” is first written using 119 squares (or cells).
2) Numbers 1 to 9 are filled inside each of these letters.
3) In total, the numbers 1 to 9 are written 13 times and the remaining cells are filled with 1 and 2.
4) We then take each Sudoku of 9 x 9 individually and fill them. The total number of squares that are covered for the word/letter are filled 1 to 9, the adjacent Sudoku (in the right) will commence with the numbers next to the last with 1 to 9 till it fills in the alphabet in that 9 x 9 Sudoku, and the next word/letter will start with the filled number.
For example, the first sudoku contains 20 squares, that are filled with 1 to 9 two times and the balance with 1 & 2. Hence the next Sudoku will commence with 3 to 9, 1 to 9, and so on.

Srinivasa Ramanujan – 100-by-100 Biography Magic Square

Ramanujan and Magic Squares

Srinivasa Ramanujan had a special affinity toward numbers. His taxi-cab number (1729) incident is popular. A Mathematician without parallel, he made extraordinary contributions to mathematical analysis, number theory, infinite series, and continued fractions. His works have been collected and analyzed throughout the world

Incidentally, in the opening page of the first Ramanujan’s notebook, there begins by working out a 3 x 3 Magic Square!

Having worked on a variety of special Magic squares ourselves, we could not think of a greater tribute to Srinivasa Ramanujan than this!

Summary

This is one of the biggest number puzzles we have done so far! This Biography Magic Square summarizes the important events that happened in the life of Sri Srinivasa Ramanujan.

The important dates in the life of Srinivasa Ramanujan were compiled from various sources. These dates were taken two digits at a time, representing either the date of the month or the month or the first/second half of the four-digit year.      As an example, Ramanujan’s date-of-birth 22-12-1887, is taken as four separate entries as    22    12    18 and 87. In short, Ramanujan’s entire life history is reproduced here, from his birth to till date in  Ramanujan-style.

Srinivasa Ramanujan 100x100 biography MagicSquare
Srinivasa Ramanujan 100 x 100 biography MagicSquare

Construction

Important dates from Ramanujan’s life were collected and these were then arranged horizontally in a row, from left to right. This row would form the top row of this biography magic square. The rest of the magic square is constructed after assembling this row.

This magic square has the properties of a conventional magic square, namely the sum of the entries along each row/column/diagonal sum up to the same magic-sum 2183.

It has these additional properties:
– starting from left to right, or, from top to bottom, we have embedded magic squares of orders 4 x 4 , 8 x 8, 12 x 12, 16 x 16, 20 x 20, and then in increased orders of 25 x25, 30 x 30, 36 x 36, 42 x 42, 49 x 49, 56 x 56, 64 x 64, 72 x 72, 81 x 81, 90 x 90, and finally 100 x 100. This is thus a cascade of magic-squares-inside-a-magic-sqaure!

Thus the total 100 x 100 Ramanujan Biography Magic square will contain the following 184 smaller magic squares of sizes as listed below:


Size of Magic Square      Number of such Magic Squares                       Total Entries


4 x 4  Magic squares          25             25   ( 4 x 4 )           =       400   squares

5 x 5  Magic squares          20             20   ( 5 x 5 )           =       500   squares

6 x 6  Magic squares          24             24   ( 6 x 6 )           =       864   squares

7 x 7  Magic squares          28             28   ( 7 x 7 )           =     1372   squares

8 x 8  Magic squares          32             32   ( 8 x 8 )           =     2048   squares

9 x 9  Magic squares          36             36   ( 9 x 9 )           =     2916   squares

10 x 10  Magic squares     19             19 (10 x 10 )          =     1900   squares


Total                                         184  (Different sized squares)   10,000   Squares


Sidenote

We have constructed a smaller 16 x 16 version of this Biography Magic Square with fewer details, which you can find here.

This was earlier published in an article “A Unique Novel Homage to the Great Indian Mathematician” in the March 2013 (Volume 23, Pg 146-147) Mathematics Newsletter published by the Ramanujan Mathematics Society. (download free).

30 x 30 Magic Squares inside a Magic Square

30x30 Magic Squares inside a Magic Square

The above is a 30 x 30 Magic Squares inside a Magic Square

This is a special construction of a Magic Square wherein we start with a small Magic Square (centermost one in the figure) and added rows and columns around it, ensuring that we have a Magic Square at each stage. This Magic Square has been color-coded to make the Magic Squares clearer.

From the center Yellow coloured is a 4 x 4 Magic square with a total of 1802 in all vertical, Horizontal and in both diagonals. When combininng with the blue coloured sqauare,  that 6 x 6  will give a totl of 2703.  Further it will expand to 8 x 8 , 10 x 10 etc… and finally it will become 30 x 30 with a grand total of 13515.

I have done this Magic squares inside the magic square from 5 x 5,     6 x 6, 7 x 7, …….198 x 198, 199 x 199 and 200 x 200.  In the 200 x 200 Magic squares inside a magic square all the numbers from 1 to 40,000 are used and the row total will be 4,00,00,100.  Also I am  planning to do it upto 1500 x 1500. 

Definitely, it is a gift given to me by Almighty.  I thank the Almighty for giving me the idea, guided me to work, and helped me to complete it with much difficulties. 

How to construct a Magic Square for a Given Date

Let us do magic square to the date of Birth of our Greatest  Indian Mathematician Sri Srinivasa Ramanujan.

His date of Birth is 22nd Dec 1887. The following is a Date-Of-Birth Magic Square with a Magic Total 139.

By following the given method we can do hundreds of, thousands of, millions of Date of Birth Magic Squares for any given date.

The following is a table with variables, which we will use in the explanation

Date of Birth Magic Square - Srinivasa Ramanujan

  1. Write the date in the top row first square, month in the second square and year in two parts in the third and fourth square.
  2. Add all the four numbers and write on the top of the square (139).
  3. Now we have to make a 4×4 magic square.
  4. Draw a empty 4×4 square and replace 22 by A, 12 by B, 19 by C and 87 by D.
  5. Now we know A,B,C and D. Rest of the values we have to find out.
  6. Count all numbers in the total 1+3+9=13. Then 1+3=4. (add all numbers and make it a single digit. Write this in the H square
  7. Now add B+C ( 12 + 18 =30). Divide 30 into two parts. i.e 14 and 16. Write 14 in W square and 16 in the Z square
  8. By using the properties of Magic square, i.e all vertical, Horizontal and both Diagonal totals are equal, we are going to solve this Magic Square.
  9. In the Fourth vertical column, we know the values of D,H,Z. we have to find Out the value of S. Hence S = 139 – (D+H+Z) = 139 — ( 87+4+16) = 139 – 107 = 32. This is the value of S. Write 32 in the S square
  10. Now in Diagonals, we know the value of A and Z . Hence the value of G+Q = 139 – (22 + 16) = 139-38= 101. Divide it into two parts 50 and 51 and write it in the F and R squares. F = 50 and R = 51.
  11. In another diagonal, we know the value of D and W . Hence the value of G+Q = 139 – (87 + 14) = 139-101= 38. Divide it into two parts 17 and 21 and write it in the F and R squares. G = 17 and Q = 21.
  12. In the second row, we know the value of E,G,H. Hence value of E=139-(E+G+H)= 139 –( 50+17+4)= 139 – 71 = 68. Write 68 in E.
  13. In the third row, we know the value of Q,R,S. Hence value of P=139-(Q+R+S)= 139 –(21+51+32)= 139 – 104 = 35. Write 35 in P.
  14. Now in the second vertical column, we know the values of B,F,Q. Hence value of X = 139 – (12+50+21) = 139- 83 = 56. Write 56 in X
  15. Now in the third vertical column, we know the values of C,G,R. Hence value of X = 139 – (18+17+51) = 139- 86 = 53. Write 53 in Y
  16. Now add the values of W,X,Y and Z. If you get 139 is the total.

Hurray!!! MAGIC SQUARE FOR 22-12-1887 IS READY

In step number 10, we have divided 101 into 50 and 51.  Instead it can be divided into q and 101 or 1 and 100 or 2 and 99 etc. etc… Interestingly we can divide it as -1 and 102 or -2 and 103 or -3 ans 104 etc.  While dividing each number, if the numbers are slightly changed, we can get a new Magic square.  

Hence we can make hundreds of, thousands of, millions of date of birth magic squares for any given date

Enjoy Magic square for your date of Birth!!!    In various methods….

How to construct a 3×3 Magic Square for a Given Total

Let the given Number be 63. We will get to the following 3 X 3 Magic-Total 63.

[table id=construct-magic-square-for-given-total-63__3x3 /]

  1. Let us do 3 x 3 magic square with Magic Sum of 63.
  2. From 63, minus 15 ( the row total of 3×3 base magic square. (63-15=48)
  3. Divide 48 by 3(since we have decided to do 3×3 magic square (48/3=16).
  4. Add one to this (16+1=17)
  5. Now start constructing a 3 x 3 magic square with 17 as the beginning number and (Top row middle – Just in the place of 1).

Note:

  • For constructing 3×3 magic square -15, then divide by 3, then add 1.
  • For constructing 4×4 magic square -34, then divide by 4, then add 1. and
  • For constructing 5×5 magic square -65, then divide by 5, then add 1.

While dividing by 3 or 4 or 5, if any fraction comes, put that fraction in all the squares. You should not delete or make it decimal.

How to construct 6 x 6 Magic square

Here is a 6 x 6 Magic Square with Magic-Total 111

       1)Draw a 6 x 6 empty square.

      2)Draw a bold line after the third square, Horizontally and vertically.

     3).Now the 6 x 6 magic square will be divided into four 3 x 3 Magic                         squares.

     4) Start filling the 3 x 3 magic square on the top left with numbers 1 to 9. and top right from 19 to 27, bottom left with 28 to 36 and bottom right with 10 to 18.

     5) Now exchange the numbers 8,5,4 from the top left 3 x 3 square to the bottommost left  3 x 3 squares with the numbers 35, 32, 31 and vice versa.

6) Your 6 x 6 magic square is ready. All vertical, Horizontal and both diagonal totals are equal ( 111) .

As per the instructions given in step no. 4, the numbers 35,32,31 will be available in the down magic square in place of 8,5,4

The FINAL FORMAT OF 6 X 6 IS GIVEN ABOVE. This will be after exchanging numbers 8,5,4 and replacee them by 35,32,31 and vice versa

How to construct a 4 x 4 magic square

This is a 4 x 4 Magic Square with Magic-Total 34

[table id=4×4-magic-square /]

  1. Draw a 4×4 empty square.
  2. Draw two diagonals.
  3. Start counting all the squares from the top left towards right.
  4. Now start writing numbers 1 to 16, count all squares and write numbers ONLY IN THE BLANK SQUARES (2,3,5,8,9,12,14,15 are to be written)
  5. Now start writing number from the bottom most right square towards left, count all squares, BUT WRITE NUMBERS ONLY IN THE SQUARES HAVING DIAGONAL LINES ONLY (1,4,6,7,10,11,13 AND 16) ARE TO BE WRITTEN.
  6. Magic square 4×4 is ready.

Note:  This method is applicable only for 4×4 magic square.  For 6×6, 8×8 there are separate methods available.