Logic Masters Deutschland e.V.

General Rules: Place a digit from 1 to 9 into each cell of the grid so that every row, column and outlined 3x3 region contains each digit exactly once.

Binary Numbers: Cells linked by a straight blue line form a binary number. Each digit contributes to the binary number according to its parity: if the digit is even, it represents a 0 bit; if it’s odd, a 1 bit. Binary numbers are read from left to right or from top to bottom. So 8-5-4-7 is even-odd-even-odd or 0101 for a value of 5.

Most binary numbers in the grid have a length of 4 bits, but be aware that some numbers in columns 6 and 7 have different lengths.

Binary Sums: Each number on the left or on the top of the grid is the sum of the values of the binary numbers present in this row or this column.

Sums within the Binary Numbers: In each of the binary numbers, it is possible to choose one to five digits that add up to the value of the number. For instance, on the right are three valid groups of cells for the 9 binary number.

10s and 11s: If and only if two neighboring digits add up to 10 or 11, a black dot separates them.