Find a great variety of ways of asking questions which make 8.
Choose any 3 digits and make a 6 digit number by repeating the 3
digits in the same order (e.g. 594594). Explain why whatever digits
you choose the number will always be divisible by 7, 11 and 13.
Find the number which has 8 divisors, such that the product of the
divisors is 331776.
Like a conventional Sudoku, this Multiples Sudoku has two basic rules:
1. Each column, row, and 3 x 3 subgrid must have the numbers 1 to 9.
2. No column, row, or subgrid can have two cells with the same number.
The puzzle can be solved with the help of the numbers which are placed on the border lines between selected pairs of neighbouring cells.
These numbers are the product of the two digits in the cells to the left and right of the clue.
For example, where there is a 12 on the line between two neighbouring cells, the cells must contain 2 and 6, or 6 and 2, or 3 and 4, or 4 and 3.
After finding the values of all the unknown digits, the puzzle is solved by the usual sudoku strategy.