|
SudokuIQ#4 [s = (x + n) mod 10]
x = Sudoku digit from 1 to 9 n = Number of the 3×3 square (see diagram next to the board) s = (x + n) mod 10 |
How to Play SudokuIQ #4
[s = (x + n) mod 10, 10 → 0]
In this version of Sudoku, the digits from 1 to 9 are encrypted using the following formula:
s = (x + n) mod 10
If the result is 10, the board shows 0.
Where:
x – a digit from classic Sudoku (1–9)
n – the number of the 3×3 square containing the cell (see the diagram next to the board)
s – the encrypted number you see on the board
How to decrypt a number from the board?
If you see 0 on the board, treat it as 10 in the encryption result.
Subtract the number of the 3×3 square (n).
If the result is less than or equal to 0, add 10.
The result is the original Sudoku digit (x).
Example – Decryption:
Cell contains 4, located in square no. 8.
4 − 8 = −4
Add 10 → 6
Original digit: 6
Second example:
Cell contains 0, located in square no. 3.
Replace 0 with 10, then 10 − 3 = 7
Original digit: 7
How to encrypt?
Add the Sudoku digit (x) to the number of the 3×3 square (n).
Divide the sum by 10 and take the remainder (mod 10).
If the remainder is 0, write 0 on the board.
Example – Encryption:
Encrypt digit 4 in square no. 6:
4 + 6 = 10
10 mod 10 = 0
Write 0 on the board.
Second example:
Encrypt digit 7 in square no. 2:
7 + 2 = 9
9 mod 10 = 9
Write 9 on the board.
Your goal:
Fill the entire Sudoku board so that, after decrypting all cells, each row, column, and 3×3 square contains all digits from 1 to 9 – according to the rules of classic Sudoku!
The diagram next to the board shows the numbering of the 3×3 squares.
Have fun!
Modulo 10 – Practical Applications in Mathematics and Logic Games
Modulo 10, meaning calculating the remainder after division by 10, is a very useful tool both in mathematics and in everyday puzzles or online logic games. This simple operation allows you to easily extract the last digit of any number, which is helpful, for example, when verifying bank account numbers or identifiers. Modulo 10 is also used to generate check digits in IT systems, and in education it serves as a method for teaching arithmetic and solving engaging math puzzles.
In online Sudoku of the SudokuIQ type, Modulo 10 is used to encrypt the digits on the board – instead of the classic numbers from 1 to 9, some cells may contain zero, which represents the number 10. This creates an extra challenge for fans of logic puzzles and modern math games. Modulo 10 works perfectly in creative Sudoku variants where you must decode hidden values, and every digit requires careful analysis.
It is worth noting that a similar rule is also used in games applying Modulo 9, but without the use of zero. If you are curious about how Sudoku with Modulo 9 works and want to test your skills in encrypting and decrypting numbers, be sure to visit: Sudoku Online – IQ #4/2.