The following numbers are to be inserted, where they will fit, into the pale blue cells.

10 digits: 3072468211, 7459873699
9 digits: 284408374, 463269159, 521617921, 978823263
8 digits: 93601245
6 digits: 268279, 352644, 534576, 790310, 857268, 930245
5 digits: 50941, 61599
4 digits: 1392, 1743, 3418, 3812, 3949, 4259, 4321, 4652, 5986, 6788, 7650, 7716, 8453, 9110, 9413, 9714
3 digits: 127, 187, 195, 246, 389, 413, 612, 735, 891, 921

There is only one 8-digit number, down the center column. There are only two 5-digit numbers (3rd and 10th rows) and the 8-digit number helps positioning them. The two 10-digit numbers flank the 8-digit number (and also imply two 3-digit horizontal numbers) and the 5-digit numbers help choosing where. The four 9-digit numbers go in the middle rows; having the 8-digit and 10-digit numbers make this easy. Having the 9-digit numbers in place help placing two 6-digit numbers in the 5th and 11th column, and this takes care of the whole center portion. Finally, you only require very little "try-and-test" for locating the 6-digit numbers in the first and last rows, which makes the rest rather quick. A good puzzle!

Posted by e.g. on 2007-07-01 22:53:25