Fill in the grid so that the grid contains the digits 1 through 9. Digits in the outside equal the sum of the three numbers of the corresponding row or column.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 3. Each row, column, and 3x3 box contains each digit three times.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 3. Each row, column, and 3x3 box contains each digit three times.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1, 3 and 5. Each row, column, and 3x3 box contains one 1, three 3's and five 5's.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1, 2 and 6. Each row, column, and 3x3 box contains one 1, two 2's and six 6's.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 2 through 4. Each row, column, and 3x3 box contains two 2's, three 3's and four 4's.

Fill in the cube so that every outlined region and every layer (as shown by the double arrows) contains the numbers 1 through 12.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9. Equal digits can be neither orthogonally nor diagonally adjazent.

Fill in the grid the digits 1 through 7 so that no row, column, and diagonal contains any digits more then once. Different colors help to spot the diagonals.