Change some digits in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9 and so that no pair of changed digits is horizontal or vertical adjazent (diagonally adjazent changed cells are allowed).

Fill in the cube so that every outlined region and every layer (as shown by the double arrows) contains the digits 1 through 8.

Puzzle:

Fill in the cube so that every outlined region and every layer (as shown by the double arrows) contains the digits 1 through 8.

Puzzle:

Fill the grid with the numbers 1 through 9. In rows, columns and 3x3-boxes no number can be repeated. Additionaly place areas of the size 3x3 in the grid. It is not allowed that these areas overlap. Each of these areas contains at least one star. In the middle cell of such area can't be a star. Moreover each star is part of exactly one of these areas. In these areas also no number can be repeated.

Put the numbers 1 through 7 into the hexagonal cells so that every line (of any length) and every zone of 7 cells marked by the rings contains every digit not more than once.

Example:

Puzzle:

Fill in the grid so that every row, 9-cell-diagonal, and 3x3 box contains the digits 1 through 9. In the shorter diagonals all digits must be different.

Puzzle:

Put the numbers 1 through 7 into the hexagonal cells so that every line (of any length) contains every number not more than once. The difference between adjazent cells is never 1.

Fill in the grids so that every row, every column and 3x3 box contains the digits 1 through 9. There must be a one-to-one correspondence between both twins, i. e., in all positions with a certain digit in the first grid must be in the corresponding position in the second grid also always the same digit (possibly another as in the first grid).

Fill in the grid so that every row, every column and the 3x3 boxes contain the digits 1 through 9. In the yellow cells there are 7 different values.