This is the same grid as above, but completed. You can see that by combining the numbers with the
mathematical symbol, you arrive at the target number.
As an example, the top-left block has two cells with the clue '6x', so this means you need to make 6 by
multiplying the two numbers, and 2x3 does make 6!
With + and x, it doesn't matter which way round your numbers go. However, with ÷ and -, the order
does matter. For Mathdoku puzzles, you can choose which way round the numbers go. So, in the bottom left
we have the clues '3 -' and '3 ÷', it doesn't matter which way round the two numbers go in the
cells. (It does of course matter for the general 'Sudoku' rule that each row/column must contain each number once and