Kakuro is a numerical puzzle that became popular starting from 2006, after the success of sudoku. It actually arrived in Italy in the beginning of the 80’s under the name of Crucisomme, published on the review Cruciverba e Passatempi.

Fill the grid with 1 to 9 digits knowing that:
• the numbers in the black spaces are the definitions: they represent the sum of the digits to be placed in the matching white spaces
• the numbers  in the lower triangles are the down definitions
• the numbers  in the higher triangles are the across definitions
• inside each sum every digit can appear just once

To solve the game you may get some help by the unique sums, downloading the “Chart of the unique sums” here on the left.